Memory Cooling

What do you guys think of after-market dram coolers?
I bought 3 Crucial DDR3 1066 modules (will upgrade to 6 in the future) and they are bare NAKID! It looks as though due to their low profile however, they should cool very well on their own (lots of room in between). Maybe I'll even point a fan at them when I get all 6 sticks in.

However just to be safe, I went ahead and bought some heat-spreaders: Vantec iceberqDDR Aluminum DDR-A1A. The major downside, as it looks like, is that they are permanent, and will void any warranty on the modules. I've read about people ripping chips off when they try to take that goo off... is it still worth putting them on? I have an IR TempGun, so I can get a fairly accurate surface temp of the mem chips when I prime the system...what are acceptable temps for these sticks???

One idea I had, is if I had to put these HS on, I could scrape the goo off and carefully put AS5 or similar on each mem chip, and then put the HS on top... Perhaps that will make it less permanent and better conducting???

Open for ideas! Not too concerned, but considering the fact that DRAM modules don't have thermal diodes, I don't want errors due to overheating when I'm compiling something perhaps....

Why fix a problem you don't have?

Well I probably won't be putting those things on, however I will if I have to. Any ideas on allowable temps by these things?