The Funiculaire is a great alternative than going up and down a ton of stairs due to the massive incline. Keep in mind when we went in March the elevator was not working, so I did have to manage some stairs to even get to the Funiculaire. There are stairs to manage getting in and out of the entry point.
It's also worth noting that the Funiculaire was closed for an hour and half over lunch which we weren't expecting, so you may want to factor this in if you have other stuff planned. It was freezing when we went, but we managed to find a small pub beside the Funiculaire which was open to have a drink and pizza while we waited to get back up the hill.
When you're on the Funoculaire the view is incredible!
As we went during March, there were no line ups. I suspect there would be huge lines in the summer so prepare for that.
It's $4.00 Canadian for a one way ride and there's souvenir shops on either end with diverse range of items you can buy.