OrangeTJ

There are tons of red dot options, but I can recommend the Vortex Crossfire. I have them on airsoft and real guns and they work great. If they can stand up to many hudreds of rounds of what my 12 gauge shooting slugs dishes out, I feel certain that they could last 100 years of continuous shooting on the MWS. There is no lighting situation in which they can't operate and present a good dot. reasonable price relative to the quality.

Honestly, since I started playing with gas blowback, I've had precisely zero interest in AEGs. My first was a GHK G5, then a G&G SMC9, and now the MWS. The other two are fun and I suspect the GHK would run even coated in mud, but the MWS is a dramatically finer piece of equipment than either of the other two. The only place where the "performance" lags an AEG in my opinion, is in the ability to just pull the trigger hundreds of times without swapping mags. All that results in is wasting bbs, really. The overall feel and experience of playing GBB makes the AEG pale in comparison and the MWS is about as good as it gets in GBBs. Had I known then what I know now, I would have just gotten the MWS in the first place and save myself quite a lot of money. I don't know about truly cold weather but I've played in temps down to about 45F (not cold, I know) with no issues at all. Frankly as a Californian I'm spoiled to warmer weather and really wouldn't want to play in freezing temps anyway, as I haven't found a good way to keep my goggles from fogging at those lower temps.

I haven't been able to find the M4 mags but have purchased 4 Type 89 mags, which work perfectly. Evike.com has them. Don't know if they ship to where you are but worth a look.