I'd have thought your friend would have learnt their lesson by now...
However, as a lover of adventure, I'm willing to help them out 1 more time...
From Braemar, the main road is slightly down hill and quite fast but fine.
The left turn at balmoral takes you up a grotty little road through the forest and out onto an exposed plateau where you can first see the Lecht and what is to come. The decent isn't too long but has a nasty offcamber right hand turn near the top.
You then rejoin a big road and take the impressive humpedback bridge and start to climb again. This climb has a tough middle and long drag to finish.
Then whoosh, down the other side before turning left to start the accent of the Lecht. A gentle valley road sees you start to climb up to Cockbridge where the fun really starts... it looks like a wall. (There is no other way to describe it). Straight up. Get in your granny gear and give it everything up to the snow gates. Whilst that is the steepest bit done there is no let up as it turns through the trees and then you head up to the left (chug chugging as you go), with a large pull off area at the top you curve right still climbing. Eventually you reach a top, and are rewarded with a slight downhill and a demoralising clear view of the road going straight up the mountain in front of you. Settle in, you're in for a long haul.
When/if you finally summit the top you can get a terrible headwind as you crawl along the flat ish top section to the ski centre. Well done for making it this far.
The decent is rapid and steep but good fun with clear sight lines until you are in the woods/across the river and a right angled left turn see the bulk of the decent over. Next comes a 4-5 miles flatish slog usually into a headwind to Tomitoul.
Next is a windy decent down to the river before and steadyish climb up the other side.
Now the best bit. Bridge of Brown. Tight steep bends going down and tight steep bends coming up the other side. Once you are up and past the coffee shop you get a lovely view of the long long drag ahead of you...
Once you have 'enjoyed' that you get a steady decent down and a hairpin left turn onto the Boat of Garten road. This is an exposed route on a barren plateau (the type to get IWRATS muttering). The last bit of the decent into Nethy Bridge is okay.
A rural farmy B-road will take you to Boat of Garten and onto the A95. The main road into Carrbidge has you climbing again - it could be a bit sketchy on a summer Saturday afternoon as it is windy and not that wide but I expect that won't apply to you.
From Carrbridge up to Slocht it is a long steady climb on the old A9. You go under an impressive bridge of the new A9 but is just lots of climbing and few bits of the standard rough A9 cycle path where the old road is no longer used by cars. Slocht is a nice climb as you also have the railway for close company.
I'll stop there as I don't want to totally put you off (and I've not been further north than Slocht).
Have fun and tell us how you get on...