I have the Pono Ohai Soprano, which may be different than the tenor... however I do not agree at all with what i read above.
This pono is very well built, and notes are right all along the neck.
The sound did not project loud when i recieved it, even though the top table is very thin. However, after 1 or 2 weeks of intensive use, it started to sound pretty much lourder and with more and more sustain slowly. My "noobish" feeling is that slowly the strings get placed correctly and the bones transmit the vibrations better than at start ? Anyway i think it is common for ukes to improve during the first few weeks, it has been reported many times.
If you only tested it for a day you certainly did not test it enough in my opinion.
Besides, it comes with Ko'Olau gold which project less than worth clear for example. Did you try with other strings?
I very barely need to tune it, mainly only when i take it out of the pouch, because i accidentely move the tuners. The Grover on it work flawless and i never need to tune it during playtimes.
It lacks some kind of ornments probably to make it nicer, and the grover are purely metal, and could have used some wooden key ends, but the aspect is the main reason for such a price. Ohai wood isnt cheap, but more available than let's say, Koa, which explains the price as well.
I do think it is a very good Uke in this price range... I will make some video review of it.
Sorry for the english mistakes, you probably understood that it isnt my native language.