As I said, Metabo farms some of their tools out to China (I vaguely recall Fein are guilty of this, too, for some models), which is a shame because they're undermining their great reputation in the industry.
PREMIUM high-horsepower motors with serious power reserves under load
(in excess of stated figures) and real overload capability, require plenty of copper in the windings, high tolerance armature balancing, high accuracy commutator machining, and high quality (both design and components) electronics.
Whenever a sub-contractor wants to penny-pinch, you can guarantee that the first thing they'll probably do is try to sneakily skimp on the copper windings.
That 230v 5" Fein grinder I mentioned has really impressed me with how gutsy it is under load (diamond cup grinding, with a shroud). Bloody hell, the thing just powers through when other grinders would go up in smoke, or at least slow down so drastically that they're hardly worth using. That kind of performance shows me that the reason the Fein weighs a ton is probably because it's got a boatload of copper in the windings. It's made me appreciate that for high-load operations (cup-grinding with an angle grinder being an ideal example), it is worth paying for a German-made motor. The Germans don't mess around with their motor windings.
Regarding Makita batteries, I know what you mean - for the most part, I have a lot of respect for Makita's tools, but they really let down a lot of trades with their bad batteries, 5yrs or so ago. A few people have told me since then that Makita star batteries are now on-par with competitors, but I don't know how true that is. I suspect it probably is true because Makita must've lost a lot of business from that cock-up, and wouldn't want to keep losing customers.
Metabo tools that use CAS batteries
(not all of their tools did, the last time I checked) have one of the very best quality battery platforms in the industry. If Metabo didn't have such a mixed bag of cordless tool offerings, and if all their cordless tools were made in Germany (which not all of them are), then I'd happily jump to the CAS platform.
I use a Fein MultiMaster OMT and their batteries only work for Fein units, which is a pain, but there you go. They recently announced that they will be migrating over to the Bosch battery platform, which I understand considering that they have co-developed the Starlock blade fitment system with Bosch. I also understand it from the point of view that Bosch do make decent battery packs (Festool's proprietary battery packs are manufactured by Bosch, too). However, I still think it's a foolish move for Fein when they could've gone with the CAS platform, which loads of highly-respected German powertool manufacturers have joined.