not 100%ly. correct for the PCE CD-Rom, but the MEGA-CD would have been capable for much more i believe, but they never really pushed that add-on, packed with a lot more hardware inside than the loose MD just had. i bought a lot of MEGA-CD games recently and i have to say now, that they not really did a great job on the most of the games, regarded what the hardware would have been capable of. not so for the PCE CD-Rom, as we all know just too well. even there was "no" addition hardware packed in.
I think that both the Genesis and Sega-CD were pushed really far, especially compared to the PC Engine (CD or Hu), even though the Sega/Mega-CD doesn't have nearly as many games. From what I understand, like some other consoles the Sega-CD hardware wasn't designed very well to utilize everything under the hood. Kinda like if you opened up your PC Engine and crazy glued in a Pentium 4 chip and closed it up. There may be some powerful components inside, but that doesn't mean that it's the sum of its parts.
But even judging many Sega-CD games by the hardware's tech specs, I think that some of the most technically impressive 16-bit console games are all Sega-CD titles.
utilize their hardware better than most PCE CD games do. Plus the cinemas in Popful Mail and Lunar EB and all the FMV crap make good use of the CD-ROM format.
We should've seen way more PCE CD games with fully animated cinemas that take up a good portion of the screen, especially for the Arcade Card. And only one japanese developer ever tried fmv. Imagine what could be done after several attempts with the Arcade Card. Not enough PC Engine games pushed or worked around the limits like lining up sprites to maximize the number on screen without hitting horizontal limits. As impressive as the handful of games are that made good use of animated tiles for background layers, they're way in the minority, there's no reason for it given the limitless storage space and so much more could've been done.
There are also few games that pushed the level of detail/shading/color and none do more than dent the hardware's potential. Non-sprite heavy games like RPG's could've made good use of higher resolutions, again especially with the CD space and larger system cards. And the amount of space for ADPCM samples is the same for CD2 games as it is for ACD games, so why hasn't every PCE CD game ever released not been loaded with sampled sfx?