As far accelerated graphics on an ISA 386 goes, that Mach64 is just about as good as it gets. I was an ATi user during the DOS era, and it wasn't as terrible as some people claim. Then again, I mostly did adventure games. The CL GD5434 based cards are really not bad in Windows, and are supposedly quite compatible in DOS. I wasn't impressed with the earlier Cirrus Logic cards acceleration abilities though. On the S3 front, I do not believe there were any 64-bit cards for ISA. The best you're going to do is the S3 928. Those have 64-bit memory with a 32-bit graphics engine. Some of those cards had up to 4MB of VRAM, and a version from #9 had 1MB DRAM + 2MB VRAM (GXE level 12?). I also have a pretty rare ELSA Winner 1000ISA that has an S3 805i chip with a 16-bit RAMDAC that seems quite nice, but I need to do further testing. I can't recall if Matrox had any models, but their DOS performance is guaranteed to be super bad. The Tseng ET4000W32i with 2MB is also a possibility, but you have to make sure your card has the 110MHz RAMDAC if want 64k colour at 1024x768 in non interlaced mode. Personally, I find the Tseng configuration software to be pretty atrocious. ATI has really nice setup and diagnostic software for both DOS and Windows. With S3 it was kind of a mixed bag, but #9 tended to have software more competitive with ATi.
The fastest ISA cards for DOS that I have are the S3 805i, the CL GD5434 and the ET4000w32i. They all performed identically.
BTW, the Mach64 is really not that slow in DOS. It's at least average. There is no performance penalty with the VRAM version versus the DRAM version (I tested both extensively). The speed gap between the Mach64 and the S3 cards is practically non existent when you're talking about the ISA versions.
"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium