When, I got my first Collings UT1 with Aquila nylgut reentrant strings I was underwhelmed. But changed the strings to Aquila reds with low g, played it until it opened up ....and BAM! It sounded terrific. Only sold it because I upgraded to UT2 mahogany.
Currently got a spruce/maple Collings tenor, an incredible sounding reentrant uke with Savarez strings. No complaints at all.