I haven't sewn on one, but the new Eversewn machines are getting great reviews from quilters. They have a range of machines. This one is their more mechanical machine:
https://www.amazon.com/Ever-Sewn-SPA...dp/B01FEI3FI6/
I think this is their newest, highest-level computerized machine:
https://www.amazon.com/EverSewn-Spar...dp/B073QYJY3Y/
By mechanical, do you mean non-computerized? Or do you mean all metal?