New member here - I am pondering the exact same question as OP
So I am finding this thread very interesting. In my case, I can get a M20 now or wait to September on a H15 - I am trying to weigh the pro’s and con’s of each bike
I initially wanted the M10, but there’s none for sale and probably won’t be any for the next year or so at LBS, so that’s out of the equation.
My thinking is that the h15 is more versatile. It will be almost as light and ride very similarly than the stock m20 and I would guess ride better than the m20 with a range extender because the extra weight is distributed evenly instead of very densely in one small area above the motor. The suspension will allow more aggressive and harsher terrain, but won't inhibit anything on light terrain, and the extra battery enables 50% more distance or a much higher proportion of boost if required. But if not required, it will make minimal difference overall. One of the main reasons for an Ebike to me is to enjoy the boost, or for long trail expeditions.
M20 on the other hand will be I expect slightly and noticeably more agile on the technical stuff, but I wonder if that is negated by the ability of the h15 to be in boost for significantly longer.
For the m20 to have the versatility of the h15 it needs a range extender, which then negates its only advantage.
I flip flop on this twice per day but I'm leaning h15. We're talking Swiss army knife vs scalpel here.
I'm also thinking the £400 saved allows purchase of a much lighter carbon bar, a lighter stem, a one-up v2 dropper post, a lightweight saddle, which should all be good for almost 500g in weight, and the potential 500 quid on the range extender gets you a pair of custom made dt Swiss wheels or even some cheap hunt trail wide wheels, which is another 250g saved (which leaves enough for a 4 pot deore caliper for the front or a minion tyre upgrade for the front and the dissect or on the back) and now you're within a kilo of the carbon bike but with an absolute beast that is better than the h10.
Of course you could do the same upgrades to the m20 and then it would be even lighter, but that fundamentally doesn't change the character of the bike like having a larger stock battery allows.
I've told my LBS to reserve an h15, but I may switch depending which one comes in first. The alloy bikes will be in higher demand in Feb when shops get stock so this leaves me with more options.
Final point is, when out on the trail with the h15 I am doubtful anyone will have a regret they didn't get the carbon, because it will do what it does and be great. However with the carbon at 360wh I can imagine some wanting the boost more without range anxiety, or crunching down a particularly rough trail, and wishing they had gone h15 for less cash.
Oh and also, for those like me with fantasies of enormous all day epic treks in the alps or Scottish Highlands, maybe even an overnighter, the h15 could take a range extender, still be lighter than a FF but with an absolutely titanic battery size. So again even more versatile.
The guy in the lbs wants a bike and says he is desperate for an h15, but may have to "settle" for an m20. This is quite telling.
With All that said, I have read a lot of threads on satisfaction with the 360wh battery and most riders feel happy with the range and for the occasion longer ride feel the range extender is always there if you want.
H bikes also come with an included shimano screen/computer.
Every time I analyse this and take out my 2006 weight weenie obsession it always comes back to the h15.
