So I have been a shelti owner for quite some time - I have had their entry level tables and eventually worked my way up to the Pro Foos tables. I also just bought one for my office...
I recently noticed that the surface on my Pro Foos at home was a little warped in the middle - you could not level it, as the issue was at the center of the play field. The ball would tend to roll towards the middle instead of staying true.
If you took a level across the table with a little bit of light you could see the 'dip'
When this table was new, it was in the $1000 dollar region - however this has to be atleast 10 years old now (they have the pro foos II and III now).
In any case, I decided to email shelti. I told them the issue, and they agreed that it was odd and that they had never seen it before. They checked around, and they cut me a deal. They got me a brand new surface for $75 bucks - as you know they are expensive (the tornado ones are upwards of $250)
Today I received the surface, installed it, and my table is as a good as new!
Not many companies will stand by their product 10 years later - most companies would send you an invoice for full price and show you where to buy it.
-still a shelti guy-