I'm a Trek fan. I haven't ridden the Lexa, but our store had quite a selection. Apparently, Health magazine just did a write up.

Ride them both and see which one wants to go home with you Ask questions--i did a lot of homework, but found the people at the various LBS's very helpful. Be honest--"i'm also looking at a Felt. What are the differences?". You may hear a little trash talk, but a good LBS is knowledgeable about other brands (poor manufacturer support, poor quality, poor wsd r&d).