The Bandit 400 was only imported for 2 or so years, 3 full model years ('91, '92, '93) and was given pretty good reviews from everything I could track down. The '91 and '92 models are virtually identical, the '93 has a 1000RPM lower red-line. It's main problem was price, you could get a bigger 600cc bike for a little more. Mind you, most magazines agreed that the 400 would out handle the slightly more expensive 600, but at the time displacement was king.
Still is, thats why a lot of people buy liter bikes as their first bike and 500cc is considered 'tiny'.
One Suzuki dealer in Florida I dealt with for parts told me that Suzuki had told them (while they looked for a new timing chain) that only 1500 GSF400's made it to North America. The entire Continent. USA and Canada! I don't know if thats true or not, it may have just been an excuse, but they are pretty darned rare. Many places I talked to wouldn't touch the bike!
I've never seen one other than mine, although I did meet someone who owned one back in the mid 90's. His words basically summed the bike up, "Corners like it's on rails and goes like crazy if you can keep her revs up".
Finding running 400s for sale is getting to be more and more difficult, finding junkers isn't. Judging from a lot of the posts I've seen, the 400 is blessed with weak capacitors in the Digital Igniter, or a weak voltage regulator that allows the caps to go bad. Many 400s were sent to scrap yards because their Igniters died. Thankfully, with the tireless research of the Bandit Alley R&D team (woefully underfunded! SEND BEER!), we've discovered how to repair these previously 'junk' Igniters and return these 'dead' bikes to life once more!