Good option, not as comfortable as a bumbag style tho IMO
For those contemplating the Downwind Week in WA this summer - The Doctor, Fig2Fig, Triple SSS, King of the Cut and Duel - all 5 events accept Type 1 inflatable PFDs - bumbag or over the shoulder style. This year all PFDs will be scrutinised by the WA Department of Transport at the Doctor - so ensure your canisters are serviced and up to date. (should be serviced every 2 years)
Note that inflatable PFD type 1 should be at the Australian standard of 150N floatation at these events. I am yet to get confirmation as to whether inflatable PFD type 1 from outside Australia will be accepted - but keep that in mind when purchasing a new PFD Type 1 inflatable.