I am actually mostly just a volunteer farm hand, working for a psychologist who keeps a couple of wild horses as pets on some very neglected cow pastures that we are trying to reclaim, and part of how I help out is by using and maintaining this tractor.
A big part of why we got it is the hydrostatic drivetrain, which seems largely solid. The psychologist grew up on the farm and likes the "idea" of a tractor, but most of the tractor work was done by her older brothers, so there is a bit of intimidation factor that comes into play if she would need to be dealing with a manual transmission, that the they hydro takes care of admirably.
She bought this at least third hand, with one of the previous owners having been an equipment rental business and another having been a State University farm program - both of which would very likely have given it copious amounts of abuse, but it seems very solid at this point, and starts easily, even in cold weather.
This came to us with a 7108Q loader package, which helps tremendously. That said, I find it frustrating that it doesn't come with a more flexible hydraulics package, and why in this day and age anyone is still using a pin style bucket attachment system when they could be building with a skid loader style quick-attach standard is just silly.
I also think it is a bit odd that they don't make both inner and outer stabilizer chains on the 3-point system, and as far as I can tell, there was no real provision at all for any rear hydraulic accessories at all (beyond the 3-point lift and optional draft of course) A quick attach frame takes care of the lack of inner chains... so long as all of your 3 point implements will actually work with a Q.A. frame.
My biggest frustration comes with continuing support from FIAT/New Holland. While they often can sell you original replacement parts for the 1620, they pretty much have a 300% markup across the board on parts, and I have yet to be able to find any of the 7 or 8 New Holland dealers within 100 miles of me to respond to e-mail inquiries or phone requests when they find out that I am asking about an older tractor... they just don't want to bother, which seems odd because it would seem logical that an older tractor owner would be the guy who would be likely to be the one next in the market for a new tractor.
At any rate, dealer stupidity aside, I am planning to add a pair of auxiliary hydraulic taps to the front of my loader so that I use a grapple bucket (or nearly any other kind skid loader attachment that uses hydraulics on the quick attach coupler I am installing) and am also looking to install a bypass switch so that I can lockout all four hydraulic systems to the back of the tractor if I need them as well.
I have plans for a hydraulic top link as well as one of the side links, which leaves a pair of auxiliary taps for mower wings, or box blade rippers or angling rear blades or any of 100 other options, including a full backhoe package, should we ever need/want one. The reality however is that this stuff is so easy to do that it really should have been done AT THE FACTORY.
I would also wish that there could be a better ag wheel configuration for this tractor that didn't rely on 24" rear discs. 24" discs just don't exist anywhere anymore, so if you ended up getting a tractor that someone put turf tires on, you are pretty much stuck with those, because unless you want to dump a grand on new wheels before you even get to tires, you are pretty much out of luck.