If you've grown accustomed to the easy maneuverability of the GT, then you're going to be disappointed in the Summer Infant. The Summer Infant is fine, but it doesn't feel like it's moving on its own like a higher-end stroller. If you don't mind expending the extra effort pushing the stroller on vacation, then you'll be able to stash the Summer Infant on the floor of the car's backseat and have lots of extra trunk space. OTOH, you can take the GT onto some unpaved terrain, but you will only be able to use the Summer Infant on paved or other flat surfaces.

We just did a california trip with a $10 umbrella stroller. I was grateful for the portability as I stuffed it in cars, hotel rooms, people's porches, etc.

Check out the gb Pockit. They sell it at Toys R Us.

We have the Maclaren Volo for just this. And subsequently it became my favorite stroller of the 3 we own.

Will you be doing anything offroad? We actually took our BOB to Portland (!) because DH likes to run and I like to sleep late. We bought the case for checking it at the gate...free! We got a funny look from the gate check people, but I was actually really grateful for it when DS was waking up at 5 am and ready to crash hard at 10 am.

We had one of those cheap $20 target umbrella strollers and worked just fined for us for our latest trip. After u figure out how to collapse it was super quick and light.

If you're not concerned about trunk space in a small rental car - then the Citi Mini is fine to bring. I personally would lean toward using what I have rather than buying something for just one trip. Can you borrow an umbrella stroller from a friend?

Umbrella is much easier.

We are traveling to California next month and taking a road trip from San Diego to LA to San Francisco with our 2 year old. Should we take our City Mini GT or get an umbrella stroller? I'm leaning towards the $75 Summer Infant 3D Lite but DH just wants to use what we already have. Any thoughts or recommendations?