As I've grown up with the Japanese PCE & haven't had to look a a turbo grafix Until later life, the Super Grafix was a big let down in design for me & i had one as a teen when I given one i looked at it & thought it was big & bulky for no reason (compared to my small white PCE)
This I found out for sure when the RF out put finally shaped off from the countless carting it about to my friends to show it off & play so I decided to opened it up & not knowing enough about electronics tried to fix it myself (Epic fail) so in the end felling defeated I gave up binned it (I still have my original copy of Battle Ace that came with the console)
but if you put the 3 incarnations of the PCE together PCE (JAP), Turbo Grafix & Super Grafix then you must admit the PCE wins every time, followed by the Super Grafix witch closely resembles the Turbo Grafix in its lay out & body shape, also if you add a CD rom unit to them all the PCE (Suit Case) look far sexier then them all & makes the other just look messy in comparison also the other take up far to much space with the rom attached.
I feel that Hudson & NEC got the PCE right the first time thats why it was so hard to better it with there other consoles (that includes shape designs & upgrade) & that why i feel there was lack of games for all the other upgraded consoles afterwards due to the love for the PCE, this also hindered the on going development & evolution of the PC Engine (e.g.: Super Grafix & PCFX)