When our cats have hairball problems we don't tend to use Science Diet because our cats have the hardest time eating it. They are such huge morsels compared to their regular meals and half the cats cannot chew them easily. Also most the time because of the big morsels the cats end up getting sick even more and making a bigger mess then the hairballs were to start with.
Some of our cats have had a harder time using the bathroom after eating them too. Some got diarrhea or constipation. Just wasn't a pretty picture.
Especially for the price you have to pay! It may be vet recommened, but every day people and shelters cannot afford to use it.

Pros: Helped some hairball problems

Cons: Size, Price, Taste, After affects

I had 3 cats on this. I can't really judge the taste... I'm the picky eater and won't try it. Jake likes it well enough, although he still keeps going for the dogfood ;). Then again, he'll go for any food he can find. He weighs close to 20 lbs, although he's finally starting to loose a little. Archie (2nd runner up in weight at 16 lbs) was doing well with this, but when he was diagnosed with CRF we had to switch to Science Diet KD and he's doing great (although we do have a hairball from time to time). Rudy lost too much, so I've switched him back to Adult Hairball control. I am very impressed with the hairball control for both the Adult and Light products. I used to find hairballs constantly, but now very, very rarely. (You'd think I'd find them from Jack, the one dog Jake has been able to train to groom HIM!)

Pros: NO HAIRBALLS!

Cons: If you insist... it could be cheaper

Science Diet hairball control does aid in preventing hairballs. My long haired cat was having an issue with hairballs and this food helped.

Pros: prevents hair balls

Cons: expensive

hills is a very good product with hairball formula.

Pros: great

Cons: nothing

I like this brand of food cause I can trust the maker of it which is Hill's Science Diet. Nala used to get a lot of frequent hairballs but since I bought this light control hairball formula, it seems to have helped a lot. It has greatly reduced the number of hairballs she used to get but now she only gets one every now and then. Even though the food is a little larger, I think this will make cats at least try to chew it better than some foods which are much smaller; and some cats like to inhale it without even chewing it, so I think this will reduce stomach upsets because cats will have at least digested the food better without swallowing the food whole. The food must taste great too because she obviously loves it.

Pros: Hill's Science Diet sure lives up to its name!

Cons: Since it is a popular brand name, this food can be expensive.