Some people refer to motor homes like boats with owners suffering from 2 foot-itis. They are never big enough. Every length has it's pro's and con's.
Introduced about 3 years ago, Phoenix has offered our particular model in two lengths. The new length is one foot longer at 24'-11" with a one foot longer wheel base. At times I wished we had that extra foot to improve interior space. On the driver-side, I'd want to make the dinette and closet longer. On the passenger side, I'd want to make the bed and galley longer.
Then again, all is well with what we have today considering we tow along with the places we end up in. I'd be in twice as much trouble with that longer wheel base. Our E350's 158" wheel base can "U"-turn on a 4 lane road with mini soft shoulders. Those 22 footers with a 138" wheel base have no worries at all being closer yet to a car.
But living in a 22 foot motor home for a month at a time versus a 31 footer, there is your flip-side argument. If you are on the fence between a 24 footer and a 27 footer, you have to weigh the pros & cons to each. And be sure to consider the place you park it when not using it. Our garage is 25'-0" deep so one more foot will still work for us. But our shorter rig in the garage allows me to access my ladders stored along that wall. Trade-offs, trade-offs.