I taken a few looks at Frey's lineup over the past couple years, and it's impressive... at a glance. The power ratings of Bafang motors (usually with throttles) far exceed anything from Bosch, Yamaha, Brose or Shimano. On Frey's higher models, they use quality major components (shocks, tires and drivetrain), but geometry considerations like chainstay length, reach measurements etc. are often sub-par for my needs. These are important considerations IMO, as they can dramatically affect handling characteristics and comfort for extended off-road excursions.
For me, the true value of an eMTB is also in details like hubs, headsets, pivots, rims etc. If they even specify these parts in their marketing endeavors, they're often generic or house brands on the Chinese models I've considered, but most times they don't list them. That's where they can hide inferior production that can cut costs and allow for Maxxis tires, SRAM drivetrains and Shimano brakes. While those familiar-named major components will likely endure for hundreds of hardy trail miles, I'd be surprised if the "minor" parts do.
As someone who rides some fairly rugged trails a few times a week year-round, these minutia matter to me. IME, even "larger" brands' bikes - iZip, Raleigh, Haibike - sometimes cut proverbial corners on these important pieces of the eMTB puzzle in order to offer competitively priced models and still make a profit. I've had to replace hubs, repack bearings and other nuance repairs much sooner than I believe to be reasonable. But then again, I used to chose big brands' lower or middling models when I began getting into eMTBs five years ago.
In contrast, my Commencal eMTB now has over 1k of the hardest miles I've ever ridden, and it's holding up incredibly well, right down to the eThirteen hubs, Cane Creek headset, and enduro pivot bearings. I sold two of my "name brand" ebikes to afford it, but it's far and away the best money I've spent on my favorite form of recreation... yet! I'm currently enamored with YT's eMTB lineup, but that's another story...
Personally, I resent hi-powered, throttled eMotos - which are often
disguised as eMTBs - due to their muddying legitimate access to traditional MTB trails. If I were to consider one, however, it'd be a Luna. They seem to use quality parts through and through, yet charge similar prices to brands that don't. Plus they're based in the USA and seem to back up their products well, offering extended warranties and replacement parts at fair prices, too.
And one last thought regarding motor submersion in water: the damage that can occur may not show up immediately, but the internals will likely suffer in the long run. To quote
Performance Line Bearings, who do a
lot of ebike motor repairs and overhauls: