I think this perk is mostly useful for people with a lot more than two Pets on their account; I for example have 36 Pets and the idea of putting them all into the resort at once sounds much nicer to me than entering them one after the other even though I have to pay more then.

The actual perk is the mass check-in, if you click that one button all your pets will be checked into the resort simultaneously xD If you have 30 pets, the additional sp cost is really worth it - but since you only have two, it's not a big deal! I personally also don't use it whenever I'm a GA, since I only own 4 pets of mine and I prefer the inn anyway (:

It's purely to save time. When you have two pets it's not so bad, putting them in separately would take about the same amount of time and be cheaper. I have 13 pets and always put them all in at once. The extra sP it costs I can win from a game of Random but it saves a lot of time.

Thanks! It seems a little obsolete for most users but I guess it's all about patience. shrug