Two complete ends of the spectrum !
They aren't that far apart either as the Pines are on the North notts border with South Yorkshire,
First of all it's only 8 miles at the Pines so go there with the intention of riding two laps and I guarantee you will be foooooked, it literally is as said above like nothing you have ever ridden, it's flat as but some how it destroys my lungs, admittedly I ride it flat out as do many others that ride there and it's great on a hard tail, I ignore the bike park as the run down the side is good fun but too short, the trail uses the ground as best it can in such a flat low lying area but if you're in the area don't dismiss it as it truly is a great little trail as long as you're not expecting huwge muhassiveness then enjoy !
Wharny, again not that long but a great place to ride and back in the day if you could ride there the saying was you could ride anywhere ! There's a lot of natural features that have been linked in to make some truly impressive riding, lots of these thread their way from a top fire road to a bottom one, I agree with the above local knowledge is key and if some one on here is local and can meet you up there this place will give you more than any black graded trail could ever imagine ! There is a decent loop which takes in some great riding and the run across the crags is one of my favourite bits of trail in the country,
Across the other side there's some DH stuff "Grenoside" this is worth a visit, worth a push up and definitely worth riding down.
Just go ride, and if you go to either please let us know,