Thanks for the poke, r1.
I'm all for part 2, if that's how people want to do it. I some some DMs already award time xp on a daily basis during adventures, and I've had no problems approving it, so it's kind of a no-brainer for a YES on that part.
As for part 1, the doubling (or tripling, or quadrupling!!) time XP... Meh. I recognize the problem all too well. Players stuck in slow games feeling like they get left behind, players in games RP-heavy games falling behind combat focused games. But I'm not convinced this is the best solution available.
RP heavy games are easily fixed: just award more xp! If you're a DM, and your players spend a month on a couple of combat encounters, then a month of solid roleplaying, you should feel absolutely free -- encouraged, even -- to award them as much xp for the RP month as for the combat month. Or more; to my mind, a month of good, solid RP is an outstanding achievement in a PbP game, and worthy of extra reward.
Slow games are a harder problem. It's a community problem, not a game mechanics problem, and I my instincts lead me to doubt that there is an easy mechanical solution. At the launch of L4W, with 1x time xp and 1x encounter xp, we found that half or more of the xp players were earning was time xp. That kind of sucked, I thought; I for one wanted to advance by killing monsters, completing quests, and roleplaying, not just by serving time. I thought that PCs that overcame more challenges and more difficult challenges, that completed more quests, should advance faster than PCs that were less active. I still kind of think that... but I also find myself growing more sympathetic to players stuck in slow games. (Like mine: sorry, Mikara!)
I don't really feel like doubling time xp is a solution for the problem that there are a bunch of slow games. I'm not going to vote no yet, but I'm not going to vote yes, either.
