Well I bought the exo terra last week and am ready to about get started. I am planning on housing tincs in here. I believe ill be going with cobalts. I am going to use the background that came with the viv and also use GS to add onto it. First question is, from what I've read it seems like tincs like a lot of ground space which is why I went with this footprint. Should I worry much about making extra levels? also, do a lot of the plants require pots built into the background, or do most of them grow onto the background/rocks/logs? Ill post progress pictures tomorrow.
Dendrobates tinctorius are a more 'heavy bodied' dart frog, and as such, occupy the lower levels and floor of an enclosure more than they will climb. Now almost all frogs climb when small, as it's a defense against predation to seek to climb and wedge themselves into a higher crack or crevice. When they are adult size and larger, you will see them utilize the floor of the enclosure quite a bit more than they would seek to climb.
Tincs of any sort are a good choice for that size enclosure - clocks out at @ 50 gallons. 2.1 is the sex ratio I would recommend to a new hobbyist.
You could certainly build 'level's in there - correctly hardsacping a viv is important but if your first attempt is less than perfect, it will not hurt the frogs. Take at long look at the build threads and pics here on DD for inspiration.
With a viv that big, I wouldn't say it's necessary; it's more of what your preferences are. Personally I like the look of levels - they add depth and visual interest via shadows within the viv, especially when combined with different lighting effects. They do provide flexibility in your plant choices - if you like the look of broms, they will make an excellent addition to well drained upper ledges. They can also provide nice platforms for cascading plants which add hides for tincs.
Echoing what Phil said, I'd say mine spend 1/4 of their time climbing on ledges, with the majority of their time in the lower levels (within 6" of the floor). They also climb in the stalks of Cypress spikemoss which is a pretty stout plant that forms lots of vertical shoots. I planted mine at the base of multiple tiered ledges and now it's a sort of tinc ladder that they use to get the to upper reaches of the viv (24" tall).
Good luck! Looking forward to the build pics!