One of the biggest factor for video shooter is ability to zoom while recording.
110HS predecessor, 100HS did not have feature while 300HS, preceding model of 310HS did. If this is important to you, I'd check it out and select 310HS if 110HS does not have this feature.
310's sensor is better in low light. It has higher capacity battery than 110HS, thus allowing for more shots per charge. 310 has greater zoom, 8x versus 5x, but 110HS starts at wider angle of 24mm, which is an advantage.
If you can find 300 HS cheaper, I would choose it over 310 HS. Otherwise, 310HS over 110HS.
