You need to define "beneficial." Are we talking about can with the ballast included or just using ordinary CFLs? Certainly any kind of fluorescent is going to have a lower operating cost and with ordinary CFLs a lower cost of purchase/replacement.

As an aside, I might suggest you rethink 6" cans. I think 4" ones are far more attractive. If you go the halogen route, PAR30 lamps offer plenty of high quality light.

FYI: I recently used about 8 par 30 regular incandescent lamps on two separate dimmers. The dimmer gets hot which I do not like but I understand this is normal. It does drive me nuts when the kids leave these on...waste of energy, cost etc.

However...When you head down stairs, there is switch (no dimmer) that lights 3 bulbs along the way to the washer / dryer. I happened to have a few Par 30 cfls and on one cfl that was the next size larger (over the washer area). I knew these would likely be left on more than the others (forgotten to be turned off). Other than the fact they take a minute to reach full brightness...I like them.

I wish I had instaleld a dimmer in my other locations that could handle the cfls/leds. I hear the dimmable cfls do not dim well but I'd like to have tried it.

"The dimmer gets hot which I do not like but I understand this is normal."

Define "hot."

Correctly rated dimmers can get warm, but I would never describe anything less than 1,000 W dimmers as being "hot."

The 1,000+ W ones often come with a heat sink on the front and a metal cover for the heat sink to prevent contact and create chimney effect to improve air flow.

Heat decreases the life span of electronics, dimmers included.

Multiple dimmers in a single box typically reduces their power handling because of heat buildup.

Using plastic face plates (or anything except metal) does not improve things.