Well, I've been eagerly awaiting this release for some time, and I have to say, at least at this point, I'm a little disappointed. Here are my very few initial hesitations:
1. The price. It's a tad steep. I have less than 100 members, so its 199 (which by the way, giving "special pricing" to all the big boys but throwing no cookie at all to the people who actually need it and charging the same price to us as 2500 member churches for a limited time?...poor form). Anyway, $199 a year? Yeah, I can do propresenter and in 2 years have it paid for and done with, comparatively to proclaim. And I read the "well what about the updates" argument, which just doesn't hold water. Most of us don't go get the latest release every year. I'm running a 7 year old version of Media shout right now, and the only complaint I have about it, is that it's on a windows platform. But the $300 (or whatever it was) that it cost me 7 years ago is in a different league than 199/pa would have been. I don't think the pricing really works in the real world of the non-mega church.
2. Uploading all my media content is potentially not worth my time. I have a lot of videos--backgrounds, looping, promotional, etc. If I transfer to pro presenter (from MS), there's no hours of uploading...I just point PP to the folder. Being a one-staff church, man, that's a lot of time away from my kids 
3. "Media Store". I don't want the media store in my app at all. Like, can't I chose in preferences for it to go away? I haven't found this option yet. But to essentially have a constant add for a $400/pa product (that I would NEVER buy) in an app that costs me 199/pa is annoying. Maybe you can take it away and I just haven't seen it yet. I dunno.
4. "Media Store". The media store is such a horrible idea that it deserves two complaints. The whole premise of this concept is that multiple people have access and can edit, create, etc., the presentation. There's no way I'd ever drop 399/pa on graphics, and to risk someone else on my team going in and either intentionally or accidentally purchasing this license is concerning.
5. Crashes. I'm sure this will be fixed eventually, because it's in beta, but this program crashed no less than 5 or 6 times while playing with it for less than 2 hours. Relatively speaking, that's 2-3 crashes per service on a sunday. No beuno for such a high priced product.
