Vests are rated for different calibers, so your thinking of supposedly stopping most anything doesn't hold water.
Surprisingly, IIa vests will stop most pistol calibers. The higher up you go, the more calibers/loadings that are stopped. In other words, higher ranked vests are inclusive of everything covered by lower ranked vests. So IIIa covers everything for IIIa, II, and IIa. II covers everything for II and IIa.
http://thefiringline.com/forums/attachment.php?attachmentid=21199&d=1163605401
If you are wearing a vest and shot by a perp, consider yourself luck if he uses hollowpoints. They are less apt to penetrate than ball ammo. The nose tends to crush in and the sides accordion out with a single fold, causing a form of expansion than helps stop the bullet from penetrating.
So if you are wearing a II-A and get hit by the 44 Magnum there may not be any penetration, but its going to be like someone just hit you with a bat accompanied by a lot of pain.
Being in pain is better than being in dead. You will like be in pain soon or later after being shot by any typical defensive centerfire caliber if wearing a soft armor vest. The Kevlar Saves book (now online and done differently) had a bunch of examples of the bruising that occurred to officers that had been shot. The amount of pain and bruising varied by situation. Some commented that it felt like they were hit with a bat. Others didn't realize they had been shot (multiple times in at least one example, IIRC) until later, the photos of the bruising being of officers in hospital beds (for observation).
If you are keeping a vest by the nightstand "just in case" it will probably be useless when the time comes because of the amount of time to put it on and adjust it. Your best bet is a front-opening vest like the older version of the Point Blank Interceptor or the Point Blank NATO.
I have gone both ways with the over the top (traditional) and the jacket styled vests. I see for there to be no more reason to have to adjust an over the top vest than there would be a jacket styled vest. If you are adjusting your over the top vest every time you are putting it on, then you are doing it very inefficiently. The trick is to put it on, adjust everything how you like it, and then take it off with opening only one side (not side and shoulder, but one side only). Next time you put it on, you only close the one side and your are good to go.
The nice thing about the over the top vest is that if you don't get it closed, it still provides frontal protection. If you don't close your jacket vest, it can come open during movement and expose your COM vitals. The nice thing about a jacket vest is that it holds hard armor plates much better and often has means by which you can attach things like a holster (such as the PB you mentioned).
.