Well, I was able to get to a playtest last night of D&D Next. Though, I didn't go in as the DM, but as a player. That is fine, since I might be able to get some players together for a playtest as a DM soonish.
I must say that I like it! I went in with three other players, well ok let me back up...
The VERY first thing I did was play with just the DM and I was running three characters. The Human priest, the dwarf fighter and the halfling rouge. I went into the cave on the right, the first one on the second level and was almost wiped out by the orcs there. The fighter went down, the priest ran off with the dwarf dragging behind him and the halfing, well the halfling couldn't do much. (I was lucky that the DM allowed for the other two members of the playtest to be nearby and ready to lend aid. POtherwise, I would have been smoked.
But, then I had help with some other players and when we started again, we were able to destroy the orc lair. We had a nearly full playtest, the only class not used was the rouge. Which I might try if given a chance down the line. I played the human priest of Pelor. However, it almost cost the dwarf his life, since the wizard decided to use grease to great effect. Then, thought using his shocking grasp would be a way to take down a prone enemy. He did not realize it might ignite the grease. Or, that pouring water on the table (which was on fire) would spread the grease fire around. (Yes, the mage wasn't thinking clearly, at all.)
Overall, I will say that the playtest was fun. I like the advantage/disadvantage mechanic. I am still sort of offput by the at-will powers of magic missile and radiant lance.
I was part of the Live Chat put on by D&D Next and they did say they would probably tone done the spells. Which, I like, yet I don't want magic missile to go back to 4E with a static number. I would say bump it back up to an actual spell. Yes, it can only be used as often as it was memorized, but giving a mage a spam button, and the priest too, felt wonky to me.
I know that without them, most people will see mages and clerics as "useless" after using their spells. A wizard or mage doesn't lose the ability to cast, he is still a mage. He has just grown tired and cannot channel the arcane forces anymore. I would say if you want to keep "spamming" the magic missile button, then that is fine. Yet, there must be a cost to it. It starts to wear away at your CON stat, or eats away at hit points or something.
However, I did think of a compromise. Allow for the magic missile to be the cantrip d4+1, yet it does not scale. The spell magic missile, that you could get at 1st level, does scale as you level up.