OT w/ multiple secondaries & triode/pentode switching

[brainstatic]

I am about to build my first 5E3 after having done a couple 5F1's over the last year or so. After swapping a number of transformers on my first 5F1 I ended up settling on Mercury Magnetics irons (if you're gonna experiment, you might as well do it on the small buggers!).

Anyways... I've chosen MM's FTDO-59M OT - this is a '59 Tweed Deluxe OT with dual secondaries - an 8 ohm tap optimized two 6L6's (5k) and an 8 ohm tap optimized for two 6V6's (8k). I figured that it was only $15 more than the basic Tweed Deluxe OT, so why not give it a try? Does anyone here have experience with this OT?

Second question... I've been debating installing a triode/pentode switch in this build. Does anyone here have any experience with this arrangement in a 5E3? How does this affect the tone?

thanks

sean