Charlie:
Mike F was right about the problems of stocking foot waders on the beach. The sand gets inside them and, in addition to making you very uncomfortable, wears holes in the waders. Bootfoots are more cumbersome but probably a better investment.
After wearing out a cheap ($120) pair of Hodgeman neoprene bootfoots (I'm hard on my boots) I decided to go with 4mm LL Bean Double L's. More expensive but very rugged and, unlike Orvis, Bean's guarantee is unlimited. With luck I might not have to purchase waders again for 20 years.
On the down side, these boots are HEAVY. When walking a long distance, I find myself envying my girlfriend who wears a light pair of Orvis Clearwaters. She's had them three years now and aside from a few easily repaired pinholes, they've held up OK.
So I guess there is no single pair of waders perfect for all occasions, always a trade-off. If you're still undecided you might consider checking out what the pros use -- not fishermen but watermen -- clammers, scallopers, etc. These guys spend half their day waist deep in water. They've probably got some good ideas on what works best.