[vortrex]

I think it's been said that there's roughly a 10% difference between the models.  I've gone from the Amadeus to the Amadeus GTA, and I could see there being a 5-10% improvement.  I think another benefit is the build materials though.  The GTA is much more substantial and quality feeling with the aluminum plinth compared to the MDF of the lesser models.  If you were buying new though and budget was an issue I would probably get the Amadeus and put the extra money into a better phono pre.

[Toaster]

Several excellent suggestions above. I'm very fond of the Rock series of turntables myself. However, having heard most of the remotely affordable decks, my tip within your budget is the Trans-Fi Salvation deck and T3 parallel-tracking tonearm. Not cheap, but amazingly good sound. Reviews around the web echo my own experience of these. Seems completely unfazed by any cartridge too, MM, MC, very low compliance or very high. My friend, who now also owns a Trans-Fi and has previously owned the Roksan Xerxes and the Rock II, both used with the SME 309 arm, has gone on a huge vinyl buying jag since buing the Trans-Fi, after years of mostly buying CDs...

[roscoeiii]

If it were me, I'd grab the Simplex that is on sale on Canuck Audio Mart, and then put the savings into a better cart. A somewhat simplified design, but all the basics of what make the Well Tempereds sound great are there.