Well, I did it. One of the players/DMs of the Old School Group opted to playtest 5E and asked us all if we wanted in. Since no one spoke up, I figured I'd give it a shot. At the very least, I would have actual data on which to draw a conclusion. At the most, I'd enjoy it. And, surprise, surprise, surprise....I actually had fun with it. Now, my initial good feelings may dwindle as I learn more about the rules and such, and as more of the rules get published. As for now, it was fun.
The "I like" parts: Skills & Feats are now Backgrounds and Themes. Easier to work with and easier to ignore if you want. Different weapons do different damage. The hit dice type and classes are same as in older editions. Silliness and creativity are still options. Electrum is back as coinage.
The "I don't like" parts: At-will spells is just too overpowered. The multiple saving throws after you reach negative HP to survive. Sleep all night = ALL hit points back, no healing magic needed. Ridiculous number of hp at 1st level. (I played a dwarf fighter. HD was a d12 and I had 20 hp at 1st level.)
Now, I read through the rules quickly so I might have missed some things. Also, this was the only game I've played, so I'm not going to go too far as I analyze this. We were scheduled to play from 12:30 to 5:30. Due to lost folks, kibitzing, bathroom breaks and time for discussion, we ended up playing for 3.5 to 4 hours. We did not test all the things in the rules, nor did Stan use all the features written on the creatures' stat blocks and such. I was the only one who got hurt, but that was due more to us roleplaying our way out of fights than actually fighting. I am curious to try this again with a tougher, more rules lawyer like DM. I think some of the things we got away with would not fly there. But, Stan did a great job of making this a fun game. I would like to play it again/some more.
So, I'll eat a little crow here and say that this game has potential to fit that little niche where a group of friends can play the different editions together almost seamlessly....if the rules are not too different from what I played. However, if the rules change too much from this, then I don't see much of a point in getting it. As Stan pointed out, for some folks there is a need for the rules to look colorful & shiny. Black & white drawings, inexpensive paperback books, and slim volumes of rules just don't look "right" to a generation used to playing video games and MMO's. And, if you can cut pieces out as easily as it looked like you could in the playtest, then those that need that color and shiny will be interested in playing it and we'll have no trouble running it.
Anyway, that was my first impressions. I'll post more later as I cogitate on the rules some more.