Need "juggling" advice-2 kids, airport - first time!

[firsttimemommy]

Ok, you guys helped me SO much with my first round of carseat/travel situation questions, so thank you!!!! I have narrowed down my scenarios and would love to know what you would do.

FYI, my kids are 5 (DD, 42 in, 39lbs) and 4 (DS, 40 in, 37lbs).

1. Take one of our current seats (Frontier, Marathon or Graco CaRgo), use in plane and rental car and just deal with the bulk of it. (this includes figuring out how to avoid taking cabs with the exception of departure and arrival, b/c if I have to use the seat in a cab to go to an attraction, I surely do not want to lug the seat around at the attraction!) I figure I can bungee the seats to our rolling carryons and put the kids in the strollers that we are gate checking: pull luggage/seat with one hand, push stroller with the other.

2. No seat in plane, Buy ridesafer harness OR Compass B510 for cab rides and rental car journey. Either of these seems much much simpler than dealing with a seat, but of course if choosing the Compass, I will have to deal with folded booster at an attraction if we take a cab.

I'm not sure why I lean towards the compass vs. the ridesafer - I know someone said it's safer to 5 pt them in no seat then 3 pt them in a seat, but it's a glitch in my thinking I guess..

So what would you do?

(edited for clarity and brevity!)

[firsttimemommy]

I shortened and edited this post for clarity (and brevity) I tend to get long winded at times....

[egoldber]

I would go with option 2 and use the harness.

[Momof3Labs]

Why will you need to take a cab if you have a rental car? I'd plan to use the rental car all the time and skip the cabs so that your kids will be in car seats when they are riding. This part has me confused so I'm not sure yet which option I'd choose.

[firsttimemommy]

sorry, in my attempt in making it more brief, I left out a few details :)

We are going to Boston for 4 days and then driving to Vermont for 4 days, so we won't pick up the rental car until we leave Boston.

We are going to try to use the T and busses mostly, but I'm worried about being tired and just *wanting* to take a cab and not being able to b/c we don't have seats with us, or wanting to take a cab to visit an attraction that is hard or slow to get to by public transport, and I have to use a seat and then lug it around the attraction once there.

Thanks - hope that makes sense now...