My goodness, you are in for a treat. Congratulations on buying that bass. I have been watching the GC used page, waiting for them to post a picture of this one. Lucky they didn't, or it might have eluded you! TUNE basses are hands down amazing.
The Bass Maniac model you've purchased will be a good starting point with the brand. Other TUNE models are perhaps to be considered higher end, if you will, but they do all play like butter.
Perhaps just as important, their sound. I don't own a Maniac, but at least the TWB and TWX series basses have a very very unique percussive quality to their notes. They as much thump you in the chest as deliver melodic content. I've been playing professionally for just about 40 years now, and consider Tune basses unique in this regard.
Presently I gig with two, plus two identical spares in the rack. Those alongside a one off LeFay and a Yamaha TRB 4P. That's the company my TUNE basses keep at gigs, and they get played a lot more than the LeFay or the Yammi.
So consider yourself TUNED!
TUNE sound is not as "hi-fidelity" as either of my other two gigging bass guitars, but plenty good sounding and again, incredible punchy. For most of the material my present band performs, that's what the songs need. I do switch over to the Yammi and the LeFay for some of the material. The only other bass I'm gigging with right now is a Daion Power Mark XX-B I got from the mfg rep in early 80's, but it's sometimes played and sometimes not.
For studio work, it's different. TUNES sound....ok....recorded. Hard to beat an old Fender in the studio.
I've heard most of the back and forth on Japanese vs. Korean TUNES. My experience is that the finish quality of the Japanese basses is perhaps more artful, grains a little more carefully chosen. Sound....not much difference. Take nothing away from the Korean basses....all 7 of my TUNES are Korean, and I love them.
There are a couple of Japanese Bass Maniacs on the bay right now, fours, I believe.
Best, Peace Out-
Kahuna