If you're still using your mtb for that 11 mile commute, you may want to consider "slick" tires - from what I understand, knobbies on the pavement compared to a road bike tire takes 4 times the energy - so in actuality, you're feel like you're riding about 44 miles. My commute is 18 miles one way, and I couldn't believe the difference! (I still ride the mtb - just use the slicks for road riding...)

Good luck, congrats on the new baby, and happy riding!