SUPER IDEA, almost well done!!!
To a great chamber you get all great 12strg guitars, dreadnoughts and also semihollow electric of old fashion, as SHERATON II and oth. are... FINE!
The small chamber takes STRAT, TELE, LES PAUL and a thin guitarra classica as Thomann Gypsy Nylon CE; at the worst (pressed) a BeatBass! The same should be probably a short hollowbody electrics, if it will be a litte more thick/fat and longer approx.5-10cm - then it absorbs the guitarra classica standart and many more! Think about it!
Also you should use for mandolins, mandola, bass mandolin...
CONCLUSION: WORKHORSE! Thick padding, sturdy material some handy details at pockets, good zips. Excepting more additional versatility of smaller chamber (enlarging), I cant find out anything wrong!
Probably - the long pocket at the neck should be splitted in two...
For a travelling multi-instrumentalist an esssential !