Here's a funny story - I bought an XL-2 in San Francisco a couple of years ago for 400 quid...
It was missing the pivot on the back (which I replaced with a Steinberger designed 'boomerang') but was still in pretty good nick. The guy selling it had bought it for next to nothing in the nineties...
It was a wonderful feeling bass with a huge, clean tone - very piano like, with endless sustain. The neck was narrow and deep (apparently Stanley Clarke advised Steinberger on the profile) and very comfortable.
It was heavy in that it was dense, but the body was tiny, so there were no fatigue issues. It was a great fun bass but I sold it to make a profit to invest in a nice j bass. I don't really regret selling it apart from not being able to say I own a bit of eighties retro design - I just didn't really need what it offered tonally. In retrospect I'm glad I got the Steiny thing out of my system. They are great, but they certainly don't replace a good P or J, which have more tonal character in my opinion.
Tonewise, they are an acquired taste in rock - while people like Geddy and Sting used Steinbergers at certain points their tone was a bit hifi and vanilla in my opinion. For Dub, though, they are f***ing amazing - just ask Robby Shakespeare or Bill Laswell! There is so much lo end in a Steinie.
And to answer your original question - the reissues and old skool lookalikes are absolutely nothing like the original Steinies in tone or feel.
Nick