Two solo tents might weigh a bit more than a single 2-person tent, but there's another advantage (besides snoring and farting, which are considerable advantages): if, in the middle of a trip, if you become separated (accidentally or by choice), it's no big deal. In fact that option is one my two best hiking buddies and I decided on long ago, P.U. (Pre-Ultralight), for all our gear. Essentially, we took solo trips together. We didn't split up often, but it was always nice to have the option.