Pros: Big difference from DDR2-800 to the DDR2-1066, you can feel it when Vista first loads up and goes into your user account. With DDR2-1066 you wont feel the split second load time and execution you feel with DDR-800. This is also noticeable with program execution and "alt+tabbing" through programs. I bought 2 of these so I have 8Gigs... GG*~! *(internet gaming talk meaning Good Game or Game OVER)

Cons: Going through forums and Google Searches, you'll find out that DDR2-1066 is not a normal speed unlike DDR2-800. DDR2-1066 is actually a buffed up DDR2-800, you have to make the adjustments in the Bios to make it run and recognize it as a DDR2-1066. You'll notice in the CPUID program that it's recognizing it as a DDR2-800 or PC2-6400. Just make sure you tweak the DDR2-1066 memory in the BIOS as CAS# Latency (CL) as 5.0 clocks, RAS# to CAS# Delay (tRCD) as 5 clocks, RAS# Precharge (tRP) as 5 clocks, Cycle Time (tRAS) as 15 clocks, Bank Cycle Time (tRC) as 26 clocks, and Command Rate (CR) as 2T. my Cycle Time (tRAS) is auto configuring to 13 clocks, but thats ok, it's running fine. But last but not least, you have to up the Memory Voltage to 2.10 volts. If you are scared to do any of these, stick to DDR2-800 and your motherboard will auto sense it as DDR2-800 no worries. Until Manufacturers make a DDR2-1066 running at 1.8 volts, it will never be a standard speed.

Overall Review: Get yourself the free-ware program of CPUID also known as CPU-Z and then check out your Memory from the TAB, all the info on your timing and everything should be there. If it's not the way you wanted it, adjust them in your BIOS or Bios tweaking program. Then recheck it with CPUID to confirm the change. Remember, the 1066 in DDR2 is not the Mhz speed, its how much it can transfer data in seconds (1066 million data transfers per second). So DDR2-1066 is actually 533Mhz I/O Bus Clock and 266Mhz Memory Clock. All this can be confusing, but it's the truth. Don't be like "ARG!! I thought its suppose to be 1066Mhz! I'm RMAing, its not the right Memory!!!"

Pros: Nice elaborate passive cooling solution. Pretty much mandatory for anything above DDR2 800 for they will get HOT!Nice compliment to the 1066 FSB cpus. Their e-mail support was pretty good in answering my questions during my setup.

Cons: OCZ told me that I should be able to do 2.0v with 1066 speeds but had to do 2.1v to get it stable. Some mobos may have issues with the tRFC setting in its SPD being too low which may require reflash to the setting of 54. So far Im not having to do this on my EVGA 780i.

Overall Review: Just some notes for newbs. Just to note that getting any RAM this is above DDR2 800, there is a 90% chance that you WILL have to manually input the setting 1066 and manually input the timmings for this RAM/s case. Mobo is not defective and nor is the SPD on yer RAM, just the JEDEC standard is still 800 for DDR2. Also if yer planning on getting this or any other 4gb kit, better use a 64bit OS unless you only want to use 2.8 gb of the kit. If yer going 32bit, go for a 2gb kit and get better timmings in the process. Also when installing Vista, make sure to install only one stick and run all the updates first before putting in the 2nd or you could get plagued with BSODs, issues with the storport.sys file.

Pros: Works as advertised.

Cons: Only had it for 2 weeks, but already missed rebates deadline.

Overall Review: Be sure to send in your rebate within 12 days if you plan on keeping this ram. This has to be the shortest rebate deadline EVER...almost a gimmick if you look at the hundreds of people who missed it on their forums. Easy solution. RMA it back and getting something else if you have the time. I will do that after my business trip not because I care about the $25 that much, but because this borderlines some sort of cheap sale trick. Good thing newegg has a 30, that's right, 30!!!!, days return policy on these.

Pros: It works, it's cheap, and is capable of some decent performance with the right system. OCZ support is also very helpful.

Cons: If you are using AMD this RAM will not run at the advertised 1066 speed unless you have a AM2+ CPU and motherboard, not just standard AM2. It still is possible to run at 1066 speeds with an AM2, but you have to mess with your cpu multiplier, HTT, memory divider, etc. Basically alot of overclocking that will probably not be possible. None of this is a con pertaining to the OCZ RAM itself, since the lack of 1066 support for any RAM is due to the AMD architecture.

Overall Review: I bought this with a rebate, and I found out that OCZ, like other companies, seem to "misplace" and "lose" alot of their customers rebate forms, so I doubt I'll be getting that money, but I really wasn't expecting it anyway... I also wish I knew about the 1066 compatibilities before I purchased this, but that's my own fault.

Pros: Looks great, runs easily at stated speeds and looks to easily overclock. So far I see no need to overclock my computer (AMD quad core 9950, Pri HD 2x 150G Velociraptor WD1500HLFS in MB soft RAID 0, 3ware 9650SE RAID controller with 4xSamsung 750GB in hardware RAID 5). Crazy Fast!!!

Cons: A bit tall, I had to squeeze in my Tuniq Tower T-120-LFB on my MB (BIOSTAR TFORCE TA790GX A2+). The top of one stick just touched the lower fins. I bent the HS fins slightly to clear the stick. Might not run stable on default loose timings. If you get errors on mem test try tightening your timings.

Overall Review: I was getting a few memory errors and I tried loosing the timings that did not help. I tried upping the memory voltage which help a little but still errors. Then I did the only thing left, manually tighten timings to rated settings. Bang no errors. Dropped voltage, ran mem test for 24 hours and rock solid! If your memory is getting errors tighten timings to rated specs and you will be very happy. :-)

Pros: Installed in EVGA 750i mobo without issue. Set BIOS timings manually to 5-5-5-15 / 1066, mobo voltage auto-set at 1.9V with no stability issues whatsoever. Haven't bothered pushing timings yet.

Cons: This memory is very heavy, and the heat piping is a bit tall. No interference with my large CPU cooler, but could be an issue in some systems.

Pros: works great right out of the box, it's automatically recognized as ddr2 800 not ddr2 1066 so you have to change it manually in the bios but that isn't a problem it's something that you have to do with all 1066 ram

Cons: it wasn't free?

Overall Review: the heat pipes really work

Pros: Good price. Nice heatsink that also gives a good look. Decent speeds

Cons: On the newer style (not pictured) the heat pipe is only attached at one side if you tried to install or remove by the heatsink it feels as if it could break.

Overall Review: To get proper speed you must set the ram up in your bios if you go to the OCZ support forum you can find all the info you need to get it set up right. Their support forum seems very friendly and quick to respond.