YES! Get one!
My Duo is my favourite retro system. There were many different versions released, but a quick summary is:
Base systems which play credit card sized games
US = TurboGrafx / TG16
Jap = PC-Engine (white) / CoreGrafx (grey) / Coregrafx 2 (dark grey/black) / Shuttle
Portable systems which play credit card sized games
US = Turbo Express
Jap = PC-Engine GT / PC-Engine LT (semi portable with big lcd screen)
CD Addon hardware for the base consoles
US = TGCD (black)
Jap = PC-Engine CD (white, to match original PC-Engine)
Combined card/CD systems
US = Turbo Duo
Jap = PC-Engine Duo, Duo-R, Duo-RX
Odd one out that plays its own special games
Jap = SuperGrafx
Right, the next bit may be a bit tricky... so read carefully!
The cards and CDs came in both US and Jap formats.... all CD systems will read both CD formats. US consoles will read US cards and Jap cards (with a hard-to-find convertor), Jap consoles will only read Jap cards unless you do a hardware mod (not many people like to hack the Jap consoles as the US ones are much cheaper if you just want to play any of the US versions of the cart games). The SuperGrafx can be treated as a Jap base console, except that it also plays special supergrafx games that took advantage of its extra hardware (dont worry, there were only 5 or 6 games made for it - ghouls n ghosts, battle ace, aldynes, granzort, erm... something else and a special version of Darius that is also playable on normal consoles.).
All base consoles apart from the Shuttle can be hooked up to one of the CD addons and an option card (a system card, super system card or arcade system card = extra memory and cd rom routines) to play virtually the entire library of games.
To play the majority of games out there the best combo would be....
[a US Turbo DUO to play US/Jap CD's and US cards]
AND
[a Jap PC-Engine - they're just so cute! to play Jap cards] OR [a US <-> Jap convertor for the US Duo]
Of course you could get a Jap Duo and a basic US TG16 and that would give you the same effect... but Jap Duos tend to be more expensive as they look much more stylish.
Most people only remember the luke warm reception that the TurboGrafx got when it was launched in the US... they do not realise that the PC-Engine in Japan and Asia was a huge success and had a software library that dwarfs what was available for the US release. It also lasted until 1996 when the last releases were made. If you have only heard of the Turbo, then I reccomend you checkout the software catalogue for the PC-Engine... not only is it immense, but there are some absolutely amazing games amongst it.
Some links for you to look at, if you want to see some of the PC-Engine games available:
http://www.pcecp.com/index.php?mode=home [register for free and you get to see many more images of the games]
http://pcenginebible.roarvgm.com/index.htm
http://nec-ro-pole.emuchina.net/ [go to downloads and offline catalogue and save a software catalogue for the card and cd based games to your pc to browse]
-John
