I've recently just done this In some ways it's pretty cool that you are then legal to go and take a plane out but there were a few things to note:
1. As everything NA there seems to be far, far, far more C172s available to rent than PA28s. If you can convert before getting there then great
2. Price is good, but not as good as the states. I hired a C172 + instructor for £100ph. I went to another airport were rental was £70ph (St Catherines)
3. RT was different. I made the calls but things that were noticable:
3.1 Callsign shortening C-ABCD is shortened as BCD
3.2 You don't seem to need to tell stations you are leaving them
3.3 Ground station call signs didn't
appear to indicate service provided
3.4 Pilots don't shy away from being verbose. Discussion of lunch options seemed completely acceptable
4. Toronto, with the large lake nearby, is very windy and air was bumpy. Not necessarily a problem, might just have been the day I was flying. Flying pax was uneasy in the aircraft
5. No landing fees! Over fly Pearson international airport, orbit the CN tower!!!! Flying as it should be.
6. Areas around Niagra seemed to have an "unofficial" name for routing and I felt that the airspace had sort of unwritten rules about heights and clearences etc. I didn't study the aviation chart closely enough to check.
7. You have to carry an "interception" check list with you!!! Not sure how often if happens there, perhaps with being close to US airspace it's a possibility. Note that flying to the US, from Canada, also requires a visa issued before travel (I'm presuming that you are a UK passport holder)
I flew with these guys
http://www.flyislandair.net/ who were based really close to down town Toronto (was a 20min ride from downtown Sheraton to airfield)
I was going to fly with these guys
http://www.stcatharinesflyingclub.com/ because they also rented out PA28s (£70GBP/hour) as well as the ubiquitous C172. They are a bit to far out of Toronto (1h 20min drive) but if you are heading towards Niagra way then they may suit better.