To sum up: on the small regional jets, the overhead bins will not hold a standard 20 or 22 inch rollaboard anyway. On them, gate checked baggage is reclaimed planeside so there is no real downside...unless the plane is overweight and your bag has to go on the next flight. On large planes, the overhead bins will hold a standard rollaboard, but if they fill up or your bag is too overstuffed to fit gate checking is more risky because there is no planeside reclaiming of bags. You will retrieve it at baggage claim with the potential of lost or delayed luggage that goes with that. The moral is, pack your truly vital necessities in your second "personal item" bag that fits under the seat in front of you, at least on the way out. On the way home, having your bag arrive sometime later than you do is not such a worry.