Hi Richard: Interesting topic!
I'll never forget my music prof back in school(years ago) lecturing to us that playing vs. practicing are two DIFFERENT things. He emphasized, that though playing recreationally is fun & definitely has valuable merits, it cannot subsititute for the time required to devote to practicing: scales, arpeggios, chord voicings/progressions, music anaylsis & memorization etc. That said, I hardly ever practice anymore
, but instead, do a lot of playing, both on and off the job. Maybe that's why I'm not appearing at Carnegie Hall now
Scott