My take after using for a few months (it was my first mod).
The switch isn't the best, but Ken will fix it for you. I believe he's started using a different switch now, hopefully more durable. My BB had the same switch and both have been replaced. Newer one in the BB.
The 10440 batteries aren't up to snuff for an all dayer, but as others have recommended, pick up a handful of extras for your day out and you'll be fine.
The BB is the better mod, and smaller overall, but the switch placement on the LS is better/perfect.