Hi g'est,
I’m going to speak in generalities here because the nomenclature for Ponos can get a little confusing and has changed from time to time. I am not sure that this holds for the baritone models.
I think the current Pono Tenor tiers are:
Base: solid body with light satin finish; mahogany neck satin finish; ebony faceplate, heel cap, fingerboard & bridge; top & side pearloid markers rope inlay rosette
Deluxe: solid wood bodies with high-gloss finish; mahogany neck with satin finish; ebony faceplate, heel cap, fingerboard & bridge, top & side pearloid markers; rope inlay rosette
Pro-Classic: solid wood body with higher grade woodgrain figuring backs & sides; with high-gloss finish; mahogany neck with satin finish; bound radiused ebony fingerboard & bridge; more & larger pearl top fret markers; side markers; various inlays rosette; wood binding top & bottom; top perfling; faceplate & heel cap woods vary; better quality Grover tuners; comes with hardshell case
Pro-Classic 5: Same as PC with better grade woodgrain figuring backs & side; fancier binding, rosette & maybe perfling; (At one time, the PC-5 came with side port, but that was dropped); fretmarkers are various materials
Masters (Discontinued Limited Run): Same as PC; hand-selected soundboard tone woods; better grade wood figuring backs & sides; arm bevel; oval side port; ebony rosette; Ebony faceplate; “P” only wood inlay Pono logo; no top fret position markers, bound fretboard with side position markers; better quality Grover tuners
All of their tenors come with bone nut and saddle; plus an adjustable neck truss rod
Most of the PC models offered slot-head and cutaway versions as well. Some had spruce and/or cedar top models
When I bought my 2017 MGT base-level mango tenor, I mentioned that I might buy a PC version in the future. The dealer said that they would be happy to sell me one, but other than the radiused fretboard, the sound from the base models sounded as good as the pricier PC versions. And they thought the satin finished base model sounded a little more open, especially the mango, compared to the deluxe high-gloss finished ones. Other than that, the playability and feel is pretty much the same. I have not done a side-by-side comparison with identical woods in the different models.
The grade of the woodgrains and figuring is, to me, higher and the finish a little better in the PCs compared to the Deluxe models. And there is more bling on the PC versions. I can’t speak to the quality of the interior construction between the models. In the Pono tenors I own, the construction is uniformly very high from the base model to the Masters edition.
Recently, I did have a problem with the quality of the mahogany neck of a base model, mango tenor pineapple I purchased. I can’t speak to the other models or sizes.
Caveat: I am only familiar with the tenors I have purchased. And from the listings of the Ponos offered by online dealers.
I hope this helps.