All in all the results of the Thermalright HR-07 are extremely good, this cooler really makes an additional fan to blow over your memory unnecessary, or alternatively, can make you cool your ram to new extends, for even higher overclock results.
The only real drawback of the cooler is the fact that the standard heat spreaders of your memory have to be removed before you can possibly install the HR-07. This not only voids the warranty of your memory, but is a hassle to do as well, and you seriously risk damaging your memory sticks when you're not careful.
Therefore I applaud Thermalright's efforts to bring the coolers to the memory manufacturers as an OEM part, as I think these coolers can certainly help to bring your memory to the next level. But then again, if you're into memory overclocking, or if you're a modding enthusiast and got some older ram without heat spreaders lying around, or if you don't mind taking them off, you should really have a look at the new Thermalright offering.
Price wise the new HR-07 can be had for around $25 (froogle), which is not very cheap as you'll need to buy two for dual channel operation. On the other hand, after market, simple heat spreaders used to cost $10-$15 as well, and a fan would set you back another $10.
In the end, here's my take on the Thermaltake HR-07 memory cooler:
+ Excellent passive cooling performance compared to standard solutions
+ Brings active cooling performance to the next level
+ An "extreme" look that should appeal to case modders
+ Easy installation (once you get the old HSP's off)
+ Excellent quality and finish
- Not very cheap (around $50 for dual channel kit)
- Possible clearance issues with large CPU coolers
- Risk of damaging and voiding warranty of your memory when removing the stock HSP
Source:Thermalright HR-07 Memory Cooler Review