I think it's a case of what you use. Lipsqueaks are highly effective for me, but that's probably because it's what I use for coaxing. Never mess with a mouse squeak call or whatever.
By the way Jay, I got the two Power Play calls you sent, as part of the giveaway contest. I took the lipsqueak one out that very night and had it in my front shirt pocket. We called a mess of coyotes in that night. It was very calm out. On one stand, there was one within 600 yards or so, when I started shining for eyes. I decided to give the Power Play a try, as my only call. Called that sucker right in. Worked like a champ and I may start using them as stand starters.
Tony