Agree with Bill, other than lacking a built-in RX antenna port and associated T/R switching, the TVTR1 is a top of the line transverter. The mixer they use is the same as in the Elecraft K3. Sensitivity is a bit less than say a K3S running natively on 630m (and presumably a TS-590 which gets great reviews for it's LF/MF RX), but that's usually not an issue for all but very quiet rural locations. Anyone who blows it up should get a prize. It's got enough protection features to make it basically indestructible.
73 Eric