You might want to check your local laws on this. I know around here it is illegal for a civvie to wear body armor. There are some exceptions but they are few and far between.
In most jurisdictions, it is illegal to wear body armor while in the commission of a felony (for the life of me I can't figure out why; if you're committing a felony, what difference does it make whether you're wearing body armor?).
I have had body armor since the riots in LA, provided by the newspaper I used to work for, so I'm somewhat familiar with the subject. Level IIIA will protect up to .44 mag and that is what I have. Mine is Spectra not Kevlar and both have their features. If you want to be protected against rifle fire you'll need at least level III, but there is one thing most people don't think about and that is blunt force trauma. If you aren't of substantial build and in good health that can kill you even though you are wearing a vest. Just a thought.
If you've had your vest since the LA riots, I strongly recommend you check the pull date on your armor plates. All soft body armor expires. Kevlar lasts longer than Spectra.gf
Where did you get your statistics about Kevlar vs. Spectra? I have had the vest since then but have only had it on 3 or 4 times since then and only one time for a full day. It has been stored in a protective case all this time and for the last 10 years here in New Mexico, a very dry and pollution free (at least in the northern region where I live) climate.