I have no first hand experience with Otari,
and while F/I the Otari 8 track may be very similar to other 8 tracks, Otari did not cater to the home-market at all. On the other hand, Tascam capitalized to-the-max on the home recording market.
I think the basic difference in the 'semi-pro' and 'pro' equipment, is that 'pro' equipment is likely to be +4/BAL operation. Some equipment runs on both -10/UNBAL and +4/BAL, switchable. I think there's nothing wrong with -10/UNBAL-type equipment, but by the spec, the +4/BAL operation should be less susceptible to line noise from outside interference, especially on longer cable runs. For the short runs of cable you have in the typical home studio, -10/UNBAL line level is fine.
In 2 tracks, I forgot to mention the Fostex E-2, which is in the 'pro' range. The E-2 runs small & large reels, high & low speed, [7.5/15ips], has a dedicatec 3rd sync track, DolbyC, and runs -10/UNBAL and +4/BAL, switchable. It's larger and heftier than a Tascam 38, believe it or not! [Don't ask me what an obscenely low price I got my E-2 for,... $202, mint!]
BTW, There's also the Fostex E-22, which is an 15/30ips version of the E-2.
On the Tascam side, besides the 32, [which runs -10/UNBAL], is the 42 and 52, as well as
the ATR-60/2. Each machine is more high end than the 32, respectively. I believe the 42 is the version that runs -10/UNBAL and +4/BAL, switchable. The 52 and ATR-60/2 are +4/BAL operation only.
How do I get such great deals on gear? I guess I'm just at the right place, at the right time, on many occasions, but definitely not as often as I'd wish! I've missed as many great deals as I've made, but I've gotten a huge amount of nice gear at really low prices, much below average.
Hint: I'm an Ebay/Tascam and Ebay/Fostex watcher, [reads: hound].