I used to use Memory Map off line it gives good elevation profiles
@ColinJ links to it often but tbh I use on line packages such ad RWGPS which are much faster for route building.
I still use it. For rural route planning it is great - you can't beat OS maps (I have a UK-wide 1:50,000 OS map on a 5 machine Memory Map license). It isn't much good in built-up areas except for following main roads straight through, but I prefer to stick to the countryside anyway so that does not bother me. The elevation profiles are great when assessing how hard a route is going to be ...
E.g.
Verdict:
tough!
Yes - MM can be a bit tedious when plotting routes because it gives no help with the routing. I have to plot all trackpoints manually. I often take an old route and edit that to give me a head start when plotting a new one. I suppose in theory I could work out where I want to go using Memory Map, and then plot my routes on one of the online services which can auto-route between points but I can't be bothered.
I export each route to my Garmin GPS as a GPX file and now put a backup copy on my phone which I could use in case of Garmin gremlins.