...with solid tops always open up noticeably faster than flat-top instruments with solid tops? The reason I ask is that I've only had this little Eastman MD505 for a few weeks. After I reset the bridge (and installed the right base under the Fishman saddle) it immediately got a lot louder. But, that was only around a week ago and it has opened up even more since then.
At first I thought it was just my technique improving (this is my first mando, after all). Then, I realized that it seemed to be getting louder and have much better sustain even when I was just tuning it. So, I started paying close attention, holding it up by the heel of the neck and strumming the open strings, and I swear that it is louder and has better sustain than the last time I checked, two days (and about three hours of vigorous chording) ago.
Maybe it's my imagination, but I know I've never had a new guitar open up anywhere near that fast. My Taylor is about eight years old and it sounds significantly better than it did new, but it was a very gradual change over hundreds of hours playing. A Seagull with a cedar top opened up faster than any other guitar I've owned - fast enough that you could really tell it was happening - but even that was over a period of weeks of playing a couple of hours every day.
Anyway, if this behavior is something peculiar to arch-top instruments I think I'm jonesin' for an arch-top guitar...