I don't own a 1730, but do have the T2 that it replaced, and based on my experience with it, if I ever come across a 1730 locally I wouldn't hesitate to buy it (assuming of course that the price was reasonable). I'm not so much a fan of the Facit portables from the 1730's era, but I'd be surprised if the standard wasn't every bit as good as the T2.

A WAG here on my part, but I think the 1730 is a "transitional" manual machine taking much from the later  T2 and then using a new carriage design which shows up later on the electrics such as the big 1820 and the bit smaller 1840/1845 machines.  This new carriage design abandoned the tube/bearing carriage rail system.  Last time you see that tube-bearing system is on the ET3 machine....which is an electrified T2.