I have no dog in this fight, but in regards to realism as mentioned in this post earlier, you aren't going to beat latex. It is the closest thing to the actual animals "voice box" as you are going to get. Also, having it in your mouth using your own "diaphragm in your chest" produces that extra realism and manipulation of the call like the real thing. I honestly can't see anyone thinking that rubbing 2 pieces of wood, wood/glass or wood/slate together could ever compete for REALISM. That being said, I'm sure there are twice as many turkeys killed with friction calls each year, hands down. The main reason for that, lack of experience and unwillingness to properly use a diaphragm. I've heard many people who will put one in there mouth 5 minutes and never make a decent sound, then toss it aside and say "that thang ain't worth crap". If I did that to every factory rifle I bought, put some cheap factory ammo in, took it to the range, shot 3 inch groups and said the gun wasn't worth a crap, I probably wouldn't have many guns in my cabinet. Instead I take the time to do things right, work up loads, shoot many times and find the best one for that particular rifle. Sure, it's not easy and it's not quick, but it's the right way to do it to achieve a top-notch rifle. A 3 inch group rifle will kill stuff all day, but not consistently. It's the same way with coyote calls. You could call up a coyote with a blade of grass in certain situations, that doesn't mean it's the way to go or the best sounding call out there.I think a lot of people get confused when the term "realism" comes up. I've used about every call out there for every animal and respect each one in its own aspect, but that doesn't mean it sounds the best. For example, all open-reed howlers have a "plastic" sound to me and nothing like a real coyote. There are plenty of real coyote sound clips on the internet, and I've yet to find one that sounds like any open-reed I've ever heard. That being said, open reeds kill a lot of yotes, but just imagine if you sounded better??? I'm always looking to improve on my calling and I think a lot of people just find a certain sound and "settle"...You can kill stuff with any call you use, but some people like the challenge of not only killing their quarry, but calling and sounding the best they possibly can. There's a lot of things associated with a hunt other than just pulling the trigger.
Another great thing about diaphragm calls is for about $7-$8 you can have a call that can do anything from a kee-kee, yelp, cluck, cutt, purr, or gobble. Most "quality" pots are $40-50+ and ranging in the $100+ range. I'll take 4-5 diaphragms in my vest any day!
I don't care what calls people use, IMO, use what works best for you. But when I hear statements saying two pieces of wood rubbed together sound better than latex, I have to disagree. Honestly, in turkey hunting, calling would only constitute only 20-25% of the actual hunt. Set-ups, camo, being able to control yourself, scouting, ability to shoot more than 25 yards all have as much or more of a factor than the actual call....
Just as stated before, it might be worth your time to take a few more hours practicing and learn the diaphragm. Not to mention its superb realism, you are "hands free" throughout the whole process. I hate fumbling around for a call while a bird is out at 50 or 60 yards. A few soft clucks on the diaphragm will put him in your lap more times that not, and you never have to move a muscle...
Good luck finding that right call out there for you, there are plenty of different one's to choose from. Hope you have a great spring season!!