I've had both, and it seems counter-intuitive, but the 810 is easier to deal with for me.
The reason is that at some point you always have to lift a 410 off the ground...to get it in or out of your vehicle, to get it on or off the stage, to stack it on your other 410, etc.
With an 810 you roll it to the vehicle, tip it over and slide it in. Same thing with most stages. Stairs are a pain with either one, but I've dragged an 810 up stairs by myself.
The 810 sounds better to my ears too. There's something rather magical about it. A pair of 410's is sho nuff loud, but just doesn't have the presence and punch of an 810 to me.
It's worth pointing out, Ampeg 810's are a different beast than anyone else's. An SVT 810 is 165 pounds. I have a Carvin that's 115. That's a big difference. Most other brands are somewhere between those 2 weights.
I personally would not haul an Ampeg 810 anywhere without roadies and headline status.