I've seen a couple people probably in the 170# range paddle the L. I tend to be more enthusiastic about bigger creek boats personally. The main advantage will be when you load them up with lots of gear though. I don't have experience with the Burn, but it has well defined edges and I wonder if you'll need to engage the boat on edge more at a lower weight.
In my experience, if you want to paddle a larger boat, it requires more commitment to paddle strong and aggressively as they generally take more effort to move than a smaller sibling. However, the payoff is more speed, riding higher over features, and the ability to carry more gear without performance loss, which can be a great thing.
If you're committed to paddling a lot, I say for it. If you're a one or two dozen days a year in the creekboat kind of guy who likes to float and make last minute corrections, it may be a mistake.