My reply echo's 6L6s'. My '74 D-40 was stiff when I first got it back in the day and at times I thought about going to the D-50 or 55. But I'm glad I stuck it out and this badboy rumbles and roars with a clarity only imagined. My friend Lee, who is in the VK Band with me, plays a D-42 or something like that, Martin. Though I play electric most of the time, I know he'd rather I keep the D-40 in the case because it justs drowns out the Martin with clear tone. He made a comment right after we met and I showed him my D-40. He said something like, "well, I know they're heavy and could be used as boat anchors". I didn't take it personally, I just strummed a few chords for him and he allowed his eyebrows to rise up with a nod of Martin-snob approval.
I do the opening to the Ozark Mountain Daredevils song, "Standing on the Rock", which starts at the 12th fret, while he plays the open G chord in the background. He ask me once to back off a little so the background could be heard better. I said play louder man, dig in a little.
Kenny, enjoy the smile your D-40 creates, it's goin' get bigger.