My big prejudice would be that it's in the South and therefore crowded and the roads not cycle friendly.
I can't imagine anywhere that's better than Lancashire; on the west of the county we've got the flat coastal plains and great riding all the way up to the South Lakes. In the middle we've got the Bowland Fells, the West Pennines, the Pennines proper, the beginning of the Yorkshire Dales and in the middle the
Ribble Valley, all quiet traffic free areas with pretty villages and plenty of great cafes.
So go on, give me a geography lesson, tell me why Surrey has always held such an allure for cyclists.
I'm from Lancashire and live in Surrey.
I never cycled in Lancashire (being a late comer to cycling) but do 5,000 plus recreational miles a year in Surrey (extending into Sussex, Kent & Berkshire ie about the same geographical spread as lancashire) - mainly on quiet traffic free roads or an amazing network of bridleways, tracks and tow path (about a 70/30 split between road and MTB).
I can ride almost from my door off road as far as the south coast (60 miles) with no more than a few linking miles of road. The other day i rode from Merton to Hedgerley near Gerard's Cross - 56 miles 40 plus off road. I've just plotted a day ride that will take me 4 miles on road then off road cross coutry to pick up the wey navigation, thence to Guildford, up onto the North Downs, along the old Drovers Road along Ranmore, past Polsden Lacy to Leatherhead, off road over Epsom Downs and back onto the road for 4 miles home. 60ish miles with 3000 feet of climbing mostly in the last 30 miles - a route i was taken on one day a year or so ago.
I totted up the other day, since starting cycling seriously 3/4 years ago, i have been on 375 rides in Surrey and neighbouring counties. More than 250 of those have been distinct routes with a variety of different groups with most of the others being local family or training rides along the towpath or round richmond park. A pretty high proportion of those 250 distinct rides have been to different pub or cafe stops.
When i go out on the bike i have a choice between the flat lands of the Thames Valley, the challenging hills of the Surrey Hills, or the rolling countryside of any of the counties mentioned.
Plus, of course it is warmer, it is drier, there are fewer snowy/frosty days than much of Lancashire!
I'm pretty sure i could go back to Lancashire and find the same range of riding, so I'm not saying Surrey is better, just that it does offer fantastic cycling!