I've had zero problems with OS4 on my SAM 440ep, sincerely.
Sharp display on 10 different monitors in high res modes, etc - things work fine, super fast refreshes, etc. Bone stock SAM 440ep. Personally, I wouldn't touch OS4 on a legacy machine with accel/gfx card, but that's just me.
Your post is very vague, I don't really see what specific things are giving you problems and on what machines. I'd love to give you a hand if I can if there's more info. I'd suspect a bad SW config or bad hardware somewhere along the chain. I'd recommend a fresh install of OS4.1 u3 and go from there to see if it resolves anything at all. I'm not familiar enough with OS4.1 on legacy machines to offer much advice, I'm afraid.
CORRECTION: I did run into an issue or two once, but it boiled down to bad hard drives that even Spinrite on the x86 side was unable to keep running for tolerable lengths of time, nothing to do with OS4 or the SAM HW.