I've had an Extrasport Osprey for about 5 years. High back, comfortable straps over the shoulders, good pockets. If I had a complaint it would be that its a bit bulky, but with a high-back all of the floatation is going to be condensed into a pretty small area in the front & back.
I'm actually looking for a new one too.... My existing one is a body glove brand that must weigh 10 lbs, and is bulky as heck. I see several nice ones that greatly reduce the bulk and should be cooler to wear, and impede my movement less than my current vest.
Now where to find one for a 60 inch chest.... that's the question. The local "Get outdoors" doesn't have a single vest in my size.
I have the Astral Ronny Fisher and it's a nice one. I like it a lot better than the Stohlquist Fisherman because the back is a lot slimmer. It has a fair amount of room for my phone and camera in the pockets and even comes with a rain hood tucked into the neck. I don't think it's really any hotter than the others as they are all going to be warm.
I highly recommend going to a place like Get Outdoors and trying on a few and sitting in a boat like the one you have, if they have it of course. I did just that the other day... Going into the store I was convinced I was going to get the Astral Ronny Fisher. But, after trying it on and sitting in an Ultimate (my kayak at home), I found I didn't care as much for it as I thought I would. I then proceeded to try on about 4 other PFDs and ended up taking home the NRS Chinook. I couldn't be happier with my purchase, but I never would've known if I'd bought online without testing a few out.
Curious as to why you didn't like the Astral with your Ultimate? I have the same boat and I think the Astral is a lot more comfortable than the Stohlquist I have with the high back pad. The Astral back is a consistent thickness and make is a lot better for me.
One of the biggest things wasn't the padding, it was the lack of lower belt at the bottom of the pfd. I have an old Lotus Designs whitewater pfd that I used for a long time that had the lower belt. I find the belt helps keep the pfd from riding up all day... To be rather blunt, I'm fat, and if I can cinch that belt around my waist, the pfd stays put. As soon as I sat down with the astral on, it wanted to start coming up. The NRS chinook has a lower belt and thus stayed put. Furthermore, the high back clears the seat back allowing me to get full enjoyment out of the first class seat (the main reason I never wore the Lotus anymore).