I bought one about 1 year ago and pretty happy with it... bought a second a month ago because I wanted to do big modification to convert one to a travel friendly guitar, cutting the body down. The main basic adjustments I would do to standard model is modify body with bellycut, round over the edge a little more for my fore arm, and round off the metal bridge ends. These mods would make it more comfortable to play for longer periods or maybe goto the HB JA-60SB model it has the bellycut and rounded top standard.
After doing massive mods on the body , headstock etc including all of the above and more- I put it all back together and it set it up again with no problem - the only downside is neck dive as the body was reduced by 30% or more - the neck is heavy... still sounds good just feels more comfortable in the hands. For under 100 euro it was a win in standard form - and as a modified guitar there is no risk so you can really go to town. The thing that makes this guitar good are the string through bridge that keeps it in tune for long periods, compact tuners, small cavities, simple electronics, bolt on neck and cheap price the ideal candidate for custom body mods.