Very true. The Mapletree Ear+ Purist has gotten a lot of good reviews here on Head-Fi and is cheaper in kit form than the Bottlehead S.E.X. (plus Mapletree is currently throwing in free shipping), so it's still worth considering for those budding DIYers out there. Both kits use single ended triodes on both stages, with no feedback. The Mapletree does appear to use higher quality output transformers than the S.E.X., so it could have an edge in the bass. The Mapletree is also probably easier to tuberoll, since the S.E.X. uses 70's television tubes. On the other hand, the S.E.X. can drive efficient speakers.
I'm also a little curious why "Doc" Bottlehead had to hang a 120 ohm resistor network in front of the headphone jack. I'm assuming this is to reduce noise, but it will also reduce the amp's control over low impedance headphones. The Mapletree kit has an output impedance of 7 ohms with only 0.2mV noise, which is pretty darn awesome.
Hard decision. I'd personally love to build both kits.