For the past two weekends I have shot two birthday parties. The first one was for a two-year-old boy and and the following weekend was for a 50-years-young lady.
For both events I have used my Think Tank belt to hold my Think Tank skin side bag containing lenses,battery,flash, and CF cards. No problems encountered. No sagging like with what I have experienced with the Lowepro belt I have used before. The think thank belt has a locking mechanism, which prevents loosening.
Below are photos from the two fun events: