The only "con" is if your utilization/available credit will be greatly affected by losing those limits. If you have enough on your other cards to keep your utilization percentage down without needing these two cards' limits, then this is a moot point.
"Pros" include getting away from annual fees, account maintenance fees, or any of that sort of thing.
Once paid off and closed, the accounts will still remain on your credit report as a "positive" tradeline, assuming they are all clear of late payments and whatnot already. you just won't be able to use the cards, so their credit limits will be removed from your available credit and utilization figures.
Speaking from past experience, though, it can feel really good to cut up those "subprime" cards.
