I have done a lot of research into the CPS system hardware and noted for the purpose of writing the magazine and it is really interesting matter!
There are a few differences between CPS1, Dash and CPS2 boards. Yes the CPS chips are the same, yes there's QSound etc but the most important changes affecting gameplay and overally quality are in the speed of the main CPU and, most importantly, the video RAM is higher in the CPS2, which allows for a much larger amount of tiles/sprites on screen. This results in much larger characters and also in more items (e.g. bullet hell shooters were not possible on CPS1 because not enough sprites on screen to create the "hell).
Also the CPS2 boards have more slots for GFX ROMs. CPS1 can accommodate max 12 MB of GFX roms whereas CPS2 can have around 40 MB. This allows including more animation frames, more graphics, and long introductions (e.g. SFZ series) that were completely absent in the CPS1 games.
All this is explained in the 4-page CPS1 vs CPS2 article on the magazine.
Tux knows for sure all the details of the hardware of the two platforms, however the max size of the GFX roms not always meets the eye - and in this case made a massive difference.
PS: the cover was made by a 14-year old girl, very very talented. She also did a poster of Darkstalkers for one past issue of Zzap!Raine. She is the daughter of a dear friend from my town, who is also my 'partner in crime' in the CreatiVision project and other projects for 2 decades now . She is really good!!