I continue to run KotBL using 5th edition. I find that ignoring the CR system and using the original monster numbers actually works just fine, so long as the party uses bottlenecking and strategic choice of when to fight and when to pack it in. Presently they are in an alliance with the orcs against the hobgoblins.
We had another player join last night. It was his very first game of D&D ever. He ended up playing one of our NPCs. I felt bad because he kept rolling very poorly, but he seemed to take it in stride. Next week I think I'm going to see if I can get him there early so he can make a character of his own.
Our party presently consists of a human wizard (necromancer) wood elf druid (circle of the land), tiefling rogue (assassin), and their NPC companions: a human fighter (no path yet), a dwarf cleric (life domain), and an orc. (straight from the Monster Manual) I've told them that if the orc gets enough exp to level, he can earn additional HD. I'm toying with the idea of allowing him to "graduate" to a 1st level fighter or barbarian, should they keep him around that long.
The new guy is interested in a paladin. That'll be an interesting mix with a necromancer wizard in the party. In fact, the only reason the NPC cleric hasn't tried to burn him at the stake is that he mostly uses fire spells in combat, resorting to the occasional necrotic spell. It'll be fun to see how their cleric reacts when he starts animating the dead... and what might the druid have to say about that as well?
The funny thing about this group is that it sort of came to me out of nowhere; the original two members are part of the Sunday group (from which I have been regrettably truant of late) who wanted to try 5e. Then they invited a friend, and she in turn invited another friend. It's weird how when I try to put together a gaming group it inevitably falls apart, but now my most stable gaming group formed pretty much by accident. They've asked me to run twice a week, but I'm not sure I can commit to that right now- my Friday group still exists (in theory) and I (in theory) have a Thursday and Sunday game I play in.
Next week, we'll continue to grudge 'gainst the hobgoblins.
Bonus highlight of the session: watching one of the players flinch visibly when the orc chief mentioned bugbears; that player had a bad experience with the bugbear in the first part of The Lost Mines of Phandelver. (I ran a demo for those two using the D&D Beginner Set.)
Double bonus highlight: The party has named their orc companion Raul/Raoul, due to their inability to pronounce his orcish name.