Can I get some expertise ? Do's Don'ts , stay away froms etc.

I like them. Have used them for years and have done a lot on in store demos with them. I currently have the Cabelas house brand in the 38lb bouyancy rating. I test them yearly and keep a couple of spare canisters ready to go in case one deploys accidently or when needed. The canisters are cheap on Ebay and Amazon. In about 15 years I have had exactly one accidental deployment. The old wives tell that they "pop" and are loud when they deply is false. It sounds like a balloon being inflated.

Best tip I can give you on the one time I actually had to use mine is DO NOT wear it too loose. When my deployed it filled up and then twisted and was actually holding my head in water. It was not terribly hard to correct in the water but an injury or being unconscious it may have been. I have since tested that by wearing them snugly as suggested and jumping in to deploy them. Never an issue since.

k cool good info. I am ready to try one for the summer heat.

I had an Onyx deploy once without me in it while it was on the seat of the boat. Sounded like a gun going off and filling the bladder sounded like a bullet whistling overhead. I literally hit the deck and dove under the console (so much for PTSD). My buddy laughed about it once we figured out what happened. So I do not care for the type where the ring dissolves in water, too much moisture and over time the ring will partially dissolve until it gets weak and deploys. I have had them deploy sitting in a boat compartment.
I prefer the hydrostatic type where it uses water pressure to deploy.

I have had the cheaper ones with just straps which can get easily tangled and harder to put on over layers in the winter. I have one that's more of a harness that is comfortable and easy to put on.
When fishing along or in inclement weather I wear one the entire time I'm on the water and it doesn't really get in the way.

Chris, I had a Mustang self inflatable for a lot of years. I still have it. It works but I have just heard so many bad stories about them that last year I went a standard style life jacket. It's bulkier and lots more uncomfortable, but I never have to worry about if it's going to work. I'm a bigger guy and want to trust the life jacket I'm wearing.

I have a 20+ year old Mustang HIT, a couple Onxy brand auto's, and I just bought myself a new Mustang Survival Elite HIT model with 28 lbs buoyancy.

The only problems I have had was one accidental auto inflate on one of the Onyx's in my storage compartment.

Like Mark mentioned make sure you wear it correctly!

Get one that fits you well and is comfortable to wear so you will actually wear it!

Onyx
Mustang
BPS/Cabelas

All good brands. Easy to find cartridges for too

Do not fall in the lake. They will deploy... At least the Oynx one did.. lol

They DO keep your head above water after you surface.

I wear the Mustang. But, the replacement cartridge for them are like 65-70 dollars. I think the re-arm cartridges for the Oynx are cheaper.

I had one do the same. Did a little research and come to find out you should replace the bobbin in the rearming kit every 3 years. Their date stamped and the one I had showed over 3 years yet I had just purchased it less then a year earlier.

Which model is the one you mentioned was comfortable and is to put on. thanks

I had 2 different Mustangs. One expanded in my rod box. The other I tested by jumping in the lake and it did NOT expand. Two total different spectrum. So I went back to traditional life jackets. That way no worries.

Just from above you can tell there are issues.
Inflatables require regular maintenance and also have had recalls..
When you are on your long awaited trip go out to your boat and discover your pfd inflated and you do not have what you need to get it in a working state are you going to wear it inflated, if not, are you disciplined enough to fix the pfd even if it means missing out on fishing for the day or whole trip?
Maybe you will take the risk of your pfd having a low chance of not inflating, have you thought about what that could mean to the people who care about you?
Of course if something did happen you would not have to explain it might have been prevented if you did not want to look so cool or took an outing or 2 to get used to having non inflatable pfd on.
I want my pfd to always work so no inflatable for me.
I use the NRS Chinook, considered gold standard by many kayak fishermen.
I do not find it hot in summer or limits my movement.

Mine was less than a year old as well and the cartridge was 3 years old as well.

Pretty much the same experience for me.