I have three T90s covering most of the Ku arc receivable here. I also have a couple of 1.2m dishes and some larger ones for Ku. The T90s work great and I do nearly all of my Ku reception with them. The larger Ku dishes are only necessary for low horizon and out-of-footprint feeds, and during torrential downpours.
I've found the T90s to be rock-solid and easy to set up. Certainly no more difficult than a motor. The farther you get off-center the larger the losses, but they're much, much smaller losses than with a traditional reflector. The center 20 degrees have miniscule losses, and the outer 20 degrees are measurable, but tolerable.
A 1.2m with a motor should always get more signal and cover a wider arc than a T90, but will cost more and is pretty much restricted to only a few (3ish) birds at a time. 1.2m offset reflectors rapidly lose sensitivity when you get just a few degrees off-axis. That may be good enough for DBS birds, but in general you'll lose FTA feeds off-axis.
You can get the price of a new T90 down below 200 USD, shipped, which might be cheaper than what you can do for a new 1.2m. If you're willing to pick-up the dish from a local shipping depot and also tell Wave Frontier that you don't want any of their LNBs included, they'll quote a more reasonable price.
Edit: I see you're in Canada, so I imagine you'll be murdered by the shipping costs. Sorry