Drive from where? I occasionally make the drive from my house 5 miles away. I think it's OK. Rock quality is generally good, and some nice lines and a good spread of grades, but probs are often pretty short, some stuff is tidal, and can suffer with damp / grease.
Depending where you are travelling from, I would choose a few venues in the County, Glen Nevis, Torridon Dumby (if you like the place) or even Glen Clova (esp. if you are keen to explore new prob potential) over Portlethen. But this is my opinion, some people really like the place.
If you do a site search on here, the place has been discussed a few times.