Memory Upgrade Questions

So I've read that my Acer Aspire 5610 is "upgradeable to 4GB using two soDIMM modules (dual channel support)" [from the manual and elsewhere], but I still have some questions:

I've read in a few places that it won't actually use all 4 (due to the system or just the 32bit Vista?), but more likely 3.5 or less. In your opinion should I just add a 2GB stick to one of my existing 2 512MB for 2.5 or go for as much as possible with 2 2GBs?

I've also read that for "dual channel support" to work that both "modules" need to be "identical (same capacity, same timings and same clock rate)". Is DCS worth it though? I mean, right now I'm thinking that just going with 2.5GB should make a huge difference, but is it stupid not go for 2x2GBs? Would even just 2 identical 1GB sticks (for 2GB total) outperform 2.5GB?

Are there any bad memory brands or are they pretty much all the same? A local store here has a 2GB stick from PNY on sale for 30$, one from Patriot for 38.99, and one from Corsair for 34.99 (all DDR2-667MHz soDIMM). They also carry Crucial and Kingston, but they're not on sale.

I'm seriously considering getting a brand new high-end laptop, but I still think this one will get plenty of use so the 30 or 40$ would probably still be well worth it. The one thing that drives me bonkers is sometimes the computer will freeze after say running firefox with a lot of tabs for awhile or playing Civ4 (yeah, I know it's not meant to work on this laptop's specs, but it can at least early on in games with the lowest detail settings). I do tend to have several programs running at once and that's with trying to keep my startup programs and services to a minimum. Will upgrading the RAM most likely solve these issues or is it more likely that everything just needs to be reformatted and re-installed? I've run various HDD and RAM checking programs thinking that something might be broken, but they come up fine.

Thanks for any help!

kq76 Newbie

shakennstirred Notebook Evangelist