I started using Perfection Turkey diaphragm calls in the late eighties. I've used just about every other production diaphragm out there and one thing in particular stands out about Perfection's Diaphragms. They are absolutely consistent and if you buy three of the same model they WILL sound the same! I've found out the hard way that simply isn't true with most of the production calls out there. I know I can buy a regular Red every single year and it will sound the same and as good as the one I used last season. One less thing to worry about.
I made my own pot call but I wanted one that was completely impervious to heat, moisture and humidity. Humidity especially will deaden the sound of many wood backed pot calls. Most plastic backed calls don't loose anything from humidity but heat does affect them. Around here that happens often enough that it's futile to use those calls on those days. Perfection's Screamin' Demon II pot call is a glass top with a Corian (CounterTop material) base. It's capable of being very loud and very soft. It's a really great call.
Check them out at http://www.perfectionturkeycalls.com/