Your range & preformance are ofc going to differ slightly from mine, with 20" wheels & completely different bikes & riders - not to mention different environments (hills & whatnot)... but I suspect you'll get ever so slightly
better overall preformance, so it doesn't matter lol
As the 'Pie has a rotor mount anyway, I'd be somewhat tempted to convert to disk... Cantilevers do work quite well in all the conditions you'd expect to use an ebike in, but with the miles I rack up they've proven somewhat frustrating. There's nothing wrong at all w/them for your application ofc, it's simply something that is a possibility if you've access to a welder (mount) & for just $35 bucks or so:
Avid BB5 caliper & rotor
...but my disgruntlement w/rim brakes has very little correlation w/your application I'll admit - it's the hard Maine winter miles w/my two stroke that's cause me to seek other braking alternatives, that' not exactly a concern you need worry 'bout lol
"How hard was it to install the cluster on the hub motor? I've never worked on clusters."
I spun it on (by hand) and was done - it's as easy as that... unless you want it back off again in which case you'll need the cassette/freewheel tool - which may be slightly different than the one you can get at the local bike shop as the 'Pie's axle is larger:
http://www.goldenmotor.ca/products/Freewheel-Tool.html ...but the cassette itself is the same, so compatibility isn't an issue.
There is however a slight problem I encountered I should mention - my bike's rear derailleur hits the 'Pie's housing when I'm in it's last gear (7sp), scratching the 'Pie and ofc not working as it should. They include spacers to account for this, but when I installed one to try and resolve the issue, the axle's centering was thrown off & the wheel wobbled... so my "solution" was to remove the spacer and jus' not use that last gear at all...
That isn't a "fix" ofc, but as this bike is just a test platform, the 'Pie is going back on the taddy at some point and the taddy's derailleur doesn't hit - I figured it good 'nuff for me *shrug* but if ya don't wanna scratch the heck out of your new hub - you'll wanna keep a careful eye out for that when installing/testing it out.
*edit*
I had the thought I should prolly clarify what I meant with: "in all the conditions you'd expect to use an ebike in" to avoid concern...
I didn't mean weather conditions, even harsh ones... as Murphy would have it, no sooner than I got all of the 'Pie's wiring sorted out and everything working well - Maine's brief spat of unseasonably nice weather ended and it commenced raining, reverting back to the cold dreary blech it's known for this time of year. Sometimes just a misty drizzle, sometimes a torrential downpour, then a sunny day thrown in just to confound - the thermometer was all over the place in schizophrenic confusion from flirting with freezing to T shirt weather... if it wasn't pouring out.
Wincing at the irony, I continued testing the 'Pie regardless - I figured if anything this would prove the connections, even the suitability of an electric drive for my average, summertime needs. It didn't care at all in the slightest, aside from getting my shiny new stuff filthy there wasn't a single problem to be had even though everything but the batteries themselves were subject to near constant water immersion (batteries & BMS in panniers ofc).
The conditions I was inferring to are our road conditions in the winter, specifically the brutally corrosive mix of rock salt & calcium chloride. It's so bad I wouldn't put
anything I valued in it, definitely not something as sensitive as electronics... it's jus' another thing you probably don't need to worry 'bout lol