Well, maybe they aren't pro decks, but I love the 3340. I recommend firing it up and recording a bass directly in through the mic input. You can get a chance to hear what tape compression does to bass. I have been searching for a DI for years to try to get that sound in the digital world. Nothing comes close.
I never could afford one at the time, just borrowed them from friends. I had a Dokorder, which was a Teac wanna be, but it died and they went broke early on, so I let it go.
What I remember about the 3340:
The simul sync switches made the tracks being synced to sound really thin when overdubbing and I have some demos I made where you can hear the punch ins big time "KA-lunk!"
4 tracks seems so limiting now, but it forced me to think about what was really necessary for the song to work, pretty much prevented overproduction.
NO LATENCY ISSUES!!! NO UPGRADE PATH! NO PC CRASHES!
It seems like I remember those things weighing about 50 lbs. and being really awkward to move around, but those decks were the first chance I had to record multitrack without using 2 decks or bouncing with "sound on sound" on an Akai 2 track I had.
This guy restores them here in Texas: Vintage Texas
and I bet there are other places closer to you that do it as well.
Maybe it is because it was the formative years of my songwriting, but if I had a 3340 again, I would never sell it.......