Pics are Mandatory!
I was concerned that the silver strip on the front bezel of the 87s would be distracting, but it is a very dull silver color and I never notice it at all.
My last set had PIP, and though I only used it a few times (to watch two sporting events at the same time), it was nice to have it when I wanted it. I'll miss that feature during football season. However, if I understand things correctly, PIP won't work with HD signals.
I don't mind not having cablecard, a QAM tuner, or firewire, and that only leaves 1:1 pixel mapping.
Overscan can be turned off, on both the 87s and 88s, by accessing the service menu (not recommended unless you KNOW what you're doing - it allegedly voids the warranty unless done by a qualified technician), which allows 1:1 pixel mapping, but, for some reason, when the 87s are powered off, the overscan setting defaults to "on". It remains "off" on the 88s. While many report they can't tell the difference, I would like to see if I can.
The above features are the only differences between the two series of which I'm aware.