Well, I had some small issues with my 1506US, that turned out to be very small! The heads were slightly out of alignment, even causing me to think it had the 1500 headblock! I checked the numbers, and verified the block was the correct one. Just physically adjusting the heads to the tape made a huge improvement.
My strobe shows the 3 speeds are exactly on. And, this thing even sounds very good in 3 3/4 speed. IF I can find a technician locally who can work on these machines, I may eventually be able to have it professionally tuned. But, it sounds great right now.
As far as value goes...these vary widely on Ebay. I have seen them advertised for as low a $350.00, and as high as $1900.00. Everything works on mine, and it looks very good, so I don't know what it would be worth.
I have the Technics, and a Pioneer 707 in great condition. Really don't know which one I prefer to use. The 1506 takes the big reels, but the Pioneer plays both directions. And, of course...the Pioneer would be much easier to find parts for.
But, IMHO, for quality of build, sound quality, and certainly impressive appearance...the Technics is hard to beat.