DVC Sadie said:
Another plus of taking a towncar service is you get to your resort quicker therefore eliminating the long line at check-in.
Not necessarily. You limo could pull up 2 minutes after a bus full of people pulled up. By contrast, you could take DME to your resort and maybe only you and one other family get off there!
To whomever said the bus won't leave as soon as you get there. Maybe not, but MAYBE. SOMEONE has to be the last on the bus, could be you! All I know is that it took me 53 minutes from the time I got into the DME line until I was dropped off at CBR. The drive itself takes about 30 minutes, so the only "play" is in that other 23 minutes, during which I stood in the line at the DME counter, stood in line for the bus, and sat on the bus until it left.
23 minutes. Does it take significantly less than 23 minutes to wait at baggage claim, claim your bags, walk to the exit, wait for your driver to bring the car around, and then have your driver load your bags? It might be less than 23 minutes, might not. Let's say it takes 15 minutes (it could always take LONGER due to delays at baggage claim, etc.). I was happy not to part with about $120 for r/t towncar for that extra theoretical 8 minutes. I don't figure my time is worth $900 per hour. Then again, maybe it would be if I were a neurosurgeon ... or a plumber.
And to the OP, who asked about safety on the bus without car seats versus in a car with car seats. Well, during your stay you'll likely be using the Disney Transport buses to get to and from theme parks and the like. No car seats on those buses, either. If the thought troubles you that much, your only non-gut wrenching alternative is to rent a car at the airport. My wife and I had no qualms about taking our 5 and 2.5 year olds, and we're no slouches when it comes to safety: my wife is a pediatrician and I'm a therapist who works with accident trauma victims.
ENJOY WDW!