Dream Soccer 94 (dsoccr94) has it's parent rom marked as 'non working' in official FBA, but the clone dsoccr94j works in fact. And there's a note 'Imperfect sound and graphics'. It runs very slow as most other irem games.
Yes, while Irem M62/M63/M75/M77 run ok (60fps), M72/M81/M82/M84/M90/M92/M97/M107 run too slow (about 5fps).
I've done a little research http://www.system16.com/museum.php?id=4
and noticed that M62/M63/M75/M77 all use a Z80
as main CPU, while M72/M81/M82/M84/M90/M92/M97/M107 all use a V30
as main CPU (M92/M107 also use a V33
secondary? CPU). All the boards use the same sound chips (YM2151), so i guess that the main bottleneck here is the emulation of the V30 chip.
Btw: in these games (all share the same board) the game runs fine, but the sound is too slow: http://www.system16.com/hardware.php?id=945