I'm getting a glock19 and was thinking about the 2+ mag extensions I heard rumors that they tend to come apart or fall off altogether. Is there any truth or substance to this?

I've heard of problems with scherer extensions but never with GLOCK OEM or with Pearce.  It is also important you use parts that are designed for FML or NFML or you will definitely have problems.

If you get the +2 extensions, you need a longer spring. Most places sell the +2 with no spring. Your stock spring will not be strong enough to ensure reliable feeding with a +2.

Glockmeister sells a +2 kit that includes a spring. They run $12 - $14 or so per magazine. At that cost you can just by a G17 magazine. CDNN and Copes have good prices on magazines right now. (Or did last week)

If you buy G17 magazines you don't need the +2 and it will be more reliable then a 19 magazine with a +2. It will be cheaper too. And, you won't worry about the +2 doing a speed unload on you. The don't look as cool, but they work great with no modifications. Lone Wolf sells a spacer that makes the 17 magazines look better in a 19, but they aren't needed. I currently carry 17 magazines to reload my 19.

I have not heard of the new Glock OEM +2s having a problem, but you never know.

Rather then the +2 why not get G17 standard capacity mags? I have several +2s on my standard capacity mags using the stock spring and have not had a problem, along with many other people(not saying you won't as anything can happen). Now if your mags are real old then you might need new springs. If you decide you want to replace the springs, just get some stock G17 mag springs for your G19 mags, they are the same as the 10% extra power springs.  

Only have three glocks all .40:  22, 24c, & 27

have a few Dawson +5 (20 rounds) and a +8 (23)  

they work kick ass, shot open class IPSC w/ 24c w/8 moa JPoint, drop em on cement like its nothing--week after week

even though ads don't say it, they all came w/ correct springs, I'm going to buy more

so why get +2??

I have a brand new Glock 21.  I just bought two Scherer 13 round mags with the +2 already installed from Brownell's.  One mag will only load 12 rounds and the second mag will only load 13 rounds.  I shot about 350 rounds with these the mags today.  I shot Federal Hydrashock, CCI Blazer and Remington, either 230 grain ball or hollowpoint  At the end of the shoot, I could still only get 12 and 13 rounds in a so called 15 round mags.  The mag that was loaded with 13 rounds would not lock in the mag well unless I immediately loaded a round in the chamber.   I did pay $14.00 each.  Maybe this is a pay for what ya get deal.  These mags were dropped repeatedly on the deck.  I wanted to find out if the +2 extenders were going to pop off.  Neither did.  These were going to be for duty carry.  I believe that I will be going with FACTORY Glock 13 round mags.  The weapon I can depend on.  The aftermarket mags, I believe were a waste on money.  Luckily it was only $28 total.  I might be able to cut the spring down.  But would'nt Scherer take the time to find out if their mags would actually hold the rounds that they advertise that they should hold? Secondly, why would'nt Brownells find out the same thing.  They are advertising the same crap.

I have several Glock +2s on G19 and G23s with the standard spring. Strangely enough, I never had a feeding issue and especially the G19 sees a lot of range time.