I love IK, but agree with many others that it should not be turned on by default. Thanks to nerd, lesbentley, and others, there's now a pretty good set of methods to work around this "default on" problem: minfig, IK on/off PZ2s to avoid laborious one-limb-at-a-time switching, etc. And what a great idea to install those IK PZ2s as pose dots! (Thanks Wraith! I'm going to go set that up right now!)

One new hassle I've encountered recently with IK involves dynamic clothing. Coming straight from P4PP, dynamic clothing was new to me this week, and I was frustrated to find that morphed characters have to be zeroed, at least in the first few frames, so the dynamic clothing would fit. svdl's methods for ramping up morphs while leading up to an animated pose sequence works great... but a zeroed figure has straight legs. So with IK on to allow a figure to keep her feet planted while doing, say, a dance sequence, the legs get all wacky once the animated sequence begins. So here's my initial solution:

After zeroing the figure in frame 1, I bend her shins, feet and toes then move the ytrans and ztrans of her hip in frame 1 so her feet are where I want them throughout the dance sequence. For dynamic clothing which stays above the shins (or is longer but billowing so the dynamic cloth stays outside the lower limbs in frame 1), this retains the rest of the figure as zeroed so the clothing fits. The morphs are ramped up by frame 6, and the dance animation starts in frame 21. With an initial bend in the knees, the dance animation now works from frame 21 onward without the back-bending legs, and the clothing then responds to the figure morphs and drapes properly.

Like I said, I'm new to dynamic clothing so this approach, or a better one, may have been discovered already by others... but coming straight from P4PP I missed all the collective learning about dynamic cloth because I always, alas, ignored P5 threads.

So... keep IK alive (but do give people who hate it an easy-to-use kill switch)!