I have used the Randy Anderson/Primos diaphragm howlers for a long time. The "Sonic Dome" and I don't get along as well as the Double Mouth Howler, but the Double Howler has treated me well for a long time. I keep two of them in my pack at all times, and frankly, as much as I hate to say it, I play them better than open reed howlers. Most guys that play diaphragms keep theirs in the fridge to increase life, I didn't know that trick, so I never did it. I've had my first set of RA/Primos howlers for at least 7yrs, I keep them in my hunting closet in the reed box that comes with them with a piece of a toothpick separating the reeds.
I have a set of TC diaphragms that I picked up at a farm sale in a box of odds and ends. They're good calls, but I'm pretty turned off by their current marketing strategy, so I won't be spending money on MFK's in the future (TC became MFK, what, a year ago or so?).