LiPo to 5v TPS61200 vs TPS61090
No, the TPS61090 will allow you to get more efficiency and higher output current. You don't need the TPS61200's ability to run at very low input voltages. The TPS61200 is in a smaller 3mm x 3mm package vs. 4mm x 4mm for the TPS61090, but you didn't mention space being an issue.