I, simply, want to ask you to name me your TOP 3 stringing machines (current models) if you were stringing for the pros on the ATP tour. And if you can add your reason for choosing those machines as a bonus.
1) Yonex ProTech 8
Plenty of metal - other manufacturers go for plastic, extremely sophisticated tension head with adjustable pull speed, knot tension as % of reference tension, and a gigantic diabolo, fantastic clamps and clamp bases, adjustable towers, hole in each tower to put blunt awl while stringing, easy and effective turntable brake, turntable isn't massive
2) Wilson Baiardo
solid support with strong towers and improved arms, quick mounting, easy and effective turntable brake, good tension head with adjustable pull speed, knot tension as % of reference tension, and diabolo, clamp teeth pattern usually allows clamping close to frame without moving outer mains much, good clamp base design
3) Babolat Racket Station with automatic clamps
solid support with all-metal arms including the Vs, quick mounting, self-adjusting clamps, automatic clamp bases
The Star 3 is a great machine, but I didn't think of it at all since you asked about current models. I don't think that I'd go for a machine without prestretch since players often ask for a specific % of prestretch.
For the Baiardo contact Wilson. They may be able to offer you a better price for the machine depending on how much else you buy of other stuff.
Yonex Protech8 (Toyozouki String System model 8) the best craftsmanship without a doubt, buy one of their starting clamps also while you are at it.
Newest Babolat Machine (though I don't know if it is better than the sensor)
Babolat Star 4 (2502e) just because it is light. The star 4 would be my stringing machine of choice if I had to travel.