I haven't played either, but I would imagine that the Gold Tone is pretty equal in quality to the Michael Kelly Bayou (I have had experience with other Gold Tone instruments). I have never had any experience with Ozark instruments, but I'm guessing that they are probably a lot like the Regal brand resonators.
Resonators are different than other acoustic instruments due to the fact that their bodies work as a speaker cabinet as opposed to a standard acoustic; the sound of a resonator comes from the cone/bridge and the body needs to be stiff and solidly built for the sound waves to reflect off of while an acoustic instrument's body is built lighter due to the part it plays in producing the actual sound of the instrument.
Many upper end resonators (mainly square neck style) are built with laminated bodies for this reason.
This means that the less expensive, imported resonators can sound good with a little work. The set up of the cone/bridge assembly is very important.
You can replace the imported cone and "spider" bridge (if it is a "Dobro" style reso) and the wood saddles with higher quality parts (available at several different sources... Stewart MacDonald, First Quality, Cumberland Acoustic, Resophonic Outfitters, etc...). The downside is they are fairly expensive and are more fragile in construction (which is why they sound better).
Reso cones/bridges are for the most part interchangeable. There are basically three types of resonators; Dobro style reso's use a 10 1/4" cone with an aluminum "spider" bridge, National style reso's use a 9 1'4" cone with a wooden "biscuit" bridge and there is also the the Tri-Cone style which uses three smaller cones (never seen a bass version of one of these... That would be pretty cool). Reso cones obviously come in a few other sizes (for ukeleles or mandolin for example), but the ones I have listed are pretty much the standard.
Another factor is the "soundwell" which is what the cone sits on inside the body (most, but not all reso's use a soundwell, others may use a wooden ring with sound posts as well as other methods). Most higher quality soundwell are made from laminated woods (like a drum shell), though some imports use MDF or particle board. These are usually built into the body and cannot be replaced, though I have had some success saturating those types with thin super glue to make them more solid.
Sorry if I got a little off-topic. I hope this helps.