It's purely a matter of taste and decor. You'll find that the two style switches tend to have the same internal guts so there's not usually an electrical difference. I prefer the look of decora, but really there's no right or wrong answer. You can get dimmers in either configuration.

However (and please correct me if I'm wrong), if you want three-way switches with dimmers, and want to dim the light from either end, then you have to have the Decora style which have auto-dimming. For that type, if you push the top of the rocker, a series of green leds on the side move up, letting you know how bright you have it. And, importantly, the leds on the dimmer at the other end also move up. You can then control the lights from that end also. I know of no toggle-style dimmers with this capability. When our new house was built, my wife wanted toggle-style throughout so we had 3-way switches with dimmers. But, in each case, only one switch is dimmable.

These auto-dimmers are fairly pricey, ~$40 each if I remember correctly. I think they are made by Lutron and sold at HD as well as electrical supply houses.

You need a dimmer that has a matching unit for the other end. While they are more common in decora trim, Leviton at least makes them.

Thanks, Ron.

Most 3 way dimmers have the dim controlled on only one switch, the other switch is just on/off. Now if you want both switches to control dim, then you would need to look at the Lutron Maestro or the Leviton Vizia + Z-Wave.

A $320 upgrade? Unless he was going to use bargain basement toggles, this is just cash in his pocket.

JM$.02W

Vith: Yes, I want both switches to control dim. I have some of the Lutron Maestro switches, and was just inquiring about toggle equivalents, which Ron says Leviton makes.