I'm the dude with both the Alex Mk I and the Delphi Mk II. The Alex went up to Mk IV, but most you'll find are MK I. They are great tables and sound particularly good with the stock Prelude arm. I've never had any major issues with mine. I doubt you could do better new for under $1,800 or so. They are also much, much easier to set up than the Delphi. I'd say they're 90-95% of the Delphi's performance at a fraction of the cost.
Looking forward to the new Alex Mk X and Paris Mk X tables!