Even rich who runs Eagle6 says it's got problems, and if he's saying that about a feature on a SOPMOD, then it's got problems. It's not with the battery packs either, it's the power transfer system. I own 3 SOCOMs for the specific reason that numerous people out there who run the QD system batteries in the stocks on the SOPMOD/CQB-R/Recce have found issues with them after they've been used for a while. TM make good guns, their externals are generally perfectly good enough for airsoft use, but as with so many other AR-15 variant adjustable stocks (RS and AS), the Crane/VLTOR ones TM makes with the electrical contacts are hardly perfect in terms of their fitment around the buffer tube.
Unless you've got a truly nun-tight fit around the tube then your stock is going to wobble a bit. When that tolerance is the determining factor for the transfer of power from your battery to your motor and you're pulling the weapon in to your shoulder, problems are likely to arise as those metal contacts and runners start to wear. The plastic starts to get a bit worn in and as you pull the stock tight in to your shoulder, you'll may end up with a poor connection.
If that hasn't happened to you personally, that's great, genuinely, I'm pleased you've been lucky like that, but the fact remains it has happened to a fair few people out there as I've read the reports they've posted up. If it hadn't, E6 wouldn't be making reinforced/upgrade parts for that whole area of the electrics, because having read enough of Richard's posts and conversed with him a couple of times, I can tell you that the guy isn't some millionaire running a massive operation like WGC who can afford to plough thousands of pounds in to stocking products that aren't going to sell. There's diagrams around somewhere which illustrate the potential issue that can crop up, unfortunately they're buried somewhere in the behemoth SOPMOD review thread on arnies and I'm not going to try and dig for them just now, so hopefully my worded explanation will suffice.
Way around this ever potentially happening? Stick with conventional connectors. Deans, tamiya, whatever; once they're plugged in they're not going anywhere. Yes it does have its' down sides in terms of the work you can do and the parts you can fit to the front of your gun, but with a little thought they're hardly insurmountable obstacles. I'm not here to give anyone orders of course, just pass on what I've read and accumulated in my little bit of grey matter over the years. If Mr Cowin there decides the SOMPOD is the rifle for him, that's cool as beans. I'm just bringing a certain documented issue to light so that he (and various others who will lurk and read this thread) can make as well informed a decision as is feasible; and offer up my alternative option, since, in my experience, the SOCOM does work in a more consistent, reliable manner.
As for changing stocks, well I find that a very odd question to see on an airsoft forum to be honest, never ever had that crop up before. Why would I want a different one? Well.. why would anyone in the world ever want to change or upgrade any part of their weapons/gear? That's a massive part of the hobby, one of the largest in fact for a lot of people who don't have the opportunity to skirmish all that often. From my own experience, I find the absolute rock solid fit of a Magpul design with a friction lock to be very much preferable over a lot of the rather wobbly airsoft stocks out there. I also spend a lot of time looking down an ACOG or other optic, and I dislike the cheek weld of a Crane stock. In the summer it accumulates sweat and the rough plastic causes my face to itch a substantial amount, other types of stock out there cause me neither of these problems. So I'd ask you, why wouldn't I make that change? Why knowingly persist with a piece of equipment that I know to be inferior, if I have the available funds to negate the issues? That wouldn't make sense to me, but if you find the crane design to fit your personal needs well, then of course you stick with it, absolutely of course you do, that's only the sensible and smart choice for anybody to make.