I have a Seydel LLF that I love. I think the bottom reed would be rattling if I played it with as much air as you seem to be. I've also messed around with a pitch-shifter with pretty good results.
What I really love about low tuning though is how you can feel it in your hand. Every now and then my bottom reed will get stuck and I'll have to slap it against my leg. I can tell if I unjammed it because if I have the whole harp will vibrate.
How is the Thunderbird on the lips and in the hand? One of my big complaints about regular Marine Bands is how sharp they are.
The MBD's and Crossovers are much more comfortable, but if you liked recessed plates as a rule, they obviously aren't.
One thing I've noticed with all low harps - I have them in all keys except B and Ab I think - is the real low ones are breathy. In otherwords, you are much more prone to hear air through the reeds. I don't think it is the quality of the harp, but just part of their "charm".
I have three TBirds and one more enroute, all I did with them was check the gaps and make sure the plates were flush on the combs, ie. not leaking. On all three, I ended up doing zero work on anything. They remind me of Crossovers...excellent OOTB harps, but if you overdraw, they need some tweaking. ---------- Mike Quicksilver Custom Harmonicas
