The differences are in the components on the bike. Shimano components (shifters, derailleurs, etc.) come in several different levels.

Complete crap (Numered model names found on big box store bikes)
Sora
Tiagra
105
Ultegra
Dura-Ace

The intrigue 2.0 has Tiagra level components (with a 105 level rear derailleur) which are decent for a beginning bike. The Grand Sport has Sora level and a really low level front derailleur and a Tiagra rear derailleur.

I personally wouldn't get the Grand Sport. I can't comment on the Intrigue's frame, because I've never ridden one. I do have a Raleigh Competition that I love. Try out the Intrigue and some other similarly priced bikes as well. At $915 this bike is not low priced or on sale so don't feel rushed into buying it or anything. Shop around and get a feel for road bikes. Buying the first thing you see is something you don't want to do. ~$900 is a good bit of change and you don't want to end up making a bad purchase.

I'd also like to add that modern Raleighs don't seem to be very popular on these boards and you're not likely to find many people here who have experience with this particular model.