I thought the LBV was no worse than the Tac Vest. I've only ever worn it in the summer, but over a flak vest so I would have been just as hot if I had been wearing webbing or a Tac Vest. The LBV's fit was poor, and the TV has the upper hand on this factor. However, the LBV beat the TV for carrying space.
. . . lack of modularity is the biggest shortfall of both vests.