Well I don't know how many items are in your folders or how many it will take before Stacks slows to a crawl. I have never had any problems with Stacks on my lowly MacBook with GMA X3100 and a 5400 RPM drive. Then again I don't have more than 20 items in my stacks to begin with. There are still some weird issues in Finder where it'll just beachball.RIIGGGHHHT! That's exactly what I said.Okay, well I won't be replying to you anymore. I notice this in several posts across MR, I mistakenly get started with what seems to be a civil and fair argument only to be caught in your tangled web of fights.
Apple drags the old horse of "We've got it optimized this time!" every time there's a new version of OS X coming out. 10.0 to 10.2 was the most dramatic for basic responsiveness. The PowerPC 74xx hit its peak under Tiger and the G5 got a much needed boost under Leopard. Even the fan controller and thermal profiles!
You'll even get some users around here still asking why the Core Duo is supported under Snow Leopard. It makes you wonder with the lack of 64-bit drivers across the board. Maybe in 10.7 I'll get my GMA X3100 64-bit drivers. I waited so long for Santa Rosa to get kicked to the curb by Apple. You can tell from my rage.
The Power Mac G5 was sold until mid 2006 and lets not forget refurbished models afterward. I would be fun to find the last PowerPC machine on earth covered until 2010 under AppleCare.