The Ace 250 VS Compadre is not a fair comparison. The Ace is $200+ and the Compadre is $151.20.
Lots of people out there have nice used Compadres for sale for about $100-$115 shipped.
The Compadre is a great detector for tiny gold and medium depth coins.
But the Silver uMax is Tesoros best deal because it's potentially as deep as all the Tesoro models when fitted with the right coil. And you do have a decent assortment of coils from which to choose.
The Compadre has a wired on coil so there are no coil options.
Personally I'd go with either a new or used Silver uMax.
I think the Ace is also a good machine but I think you'll find a lot more with a Silver uMax or one of the earlier model Tesoros in the same category (Cutlass II, Silver Sabre, etc.,).
Badger