I just installed 4.10's and they are very nice. Around town you will barely even notice. The only thing you will notice is that the engine likes to climb through the rpms faster. The rpms are noticably higher on the highway, but really not that bad at all. Some thing like 500 rpms or so.
Seriously, do not fear the gear. It is hard to understand this until you actual get the gears, but it is not that big of a deal to go wtih 4.10's. You will notice the car is quicker, but it is not earth shattering. 4.10's feel like the should have come stock to me. It just makes the car feel more alive, without even being close to overkill. It is not like you added a supercharger or anything where there is going to be some drastic difference.