The Daystar Quad 040 would also be a nice pds upgrade: 40mhz 040 and (I forget) either 128k or 256k L2 cache.
Logic board video is likely faster than any nubus video card for most purposes, certainly on a small screen, but nubus video has other specialized uses, as in panning & zooming, 24-bit colour at high resolution, pre-press technical applications, and the like. Some of those things can be interesting, and rather useful if doing CAD work or the like.
In the world of Nubus cards, 10/100 Ethernet was available, and there were cards to accelerate image processing, with DSP co-processors, there were sound cards for music editors, etc. Depends what you want to do.
Or, max it out with period peripherals instead. Check out Celgen’s ultimate IIfx project a year or two ago if you want to get inspired. It was a thing of beauty.