On a large planing boat, especially when solo, I'd always go auto, as I see one of the more likely risks as being ejected at speed, where either loss of consciousness or temporary disorientation from hitting the water might render a solely manual life jacket useless. The RNLI use hybrid jackets with some permanent foam buoyancy supplemented by manual air activation when needed, but they tend to be in the water a lot for rescues on the inshore boats and are always operating as part of a team, and clearly can't have a lifejacket inflating every time someone has to get in the water. I have got one of those hybrid jackets as well I picked up a while back to try out, but rarely use it.
Personally I recently bought a Spinlock Deckvest 6D to replace our very old auto ones, which has been super comfortable so far, but admittedly due to COVID and a baby it hasn't had that much use yet.
Unless you have a particularly wet boat, or frequently go out in extreme conditions, I don't necessarily see the need for Hammar inflation. It's major benefit is being pressure based so less subject to false activations when you're doing serious offshore work in harsh conditions and getting constantly soaked, but personally I've never had an issue being out year round on offshore sailing yachts and RIB's with standard auto jackets.