Ah, yeah, Virtual Machines have been implementing hardware-acceleration for some time now, but it's been a while since I checked VirtualBox's progress, and support was a bit on the sketchy side. I'll have to check it out again, though, it's been a couple years.
As for using a dated version of Game Maker, that's very true, so lately it's been more of a compatibility-related move. (Although if I can get it to run on slower machines, that'd just tickle the geek in me who loves dusting off that good ol' 40lb white tower every once and a while!) Game Maker 6 was the best, but it doesn't like Vista or Windows 7. (I know there is a program to patch games compiled with GM6 by Mark Overmars himself, but seeing as I'm dependent on versions of Windows beyond XP, I'd have to run the program every time I compile a test build.) And while Game Maker 7.0 was a step in the right direction, it axed support of Win2000 and all derivatives of Win98.
Game Maker 5.3a, however, is a great in-between for all of that. It's still very fast for something mostly software-based for rendering, (Much more so than GM5.0.) and will run on all versions of Windows from 98 to Win7, and maybe Win8 too. Since I don't need real-time sprite-rotation, (I have all the hand-rotated sprites properly organized without using too much memory.) or 3D effects for my project, I'm missing virtually nothing of importance from newer versions of the program, and syntax-wise it's almost the same. I'm continuing on GM5.3a without a problem, and I can literally guarantee it will run on Windows 98 and above, just like all those game commercials in the 90's. =P
So really, it's more of a "Do I actually need
all of those extra bells and whistles from newer versions?" than "I want this game to run on that dirt old PC in my closet too!". Just cutting the bloat, pretty much, and hopefully that will make the game run more easily on newer computers too; I'm trying to optimize it as much as I can so split-screen multi-player will actually be viable for my game, and so far I'm getting a solid 60FPS on my machine in split-screen mode. (Which is much better than my last fan game!) Assuming GM5.3a's limitations become a problem in the future, I can always convert it over to GM7.0 and call it a day, no sweat.