The cubic inches in most cases doesn't come from the cylinder overbore...it's from the stroke. Most stroker kits are used with .030" overbore. The displacement comes mainly from the crank stroke.
It also depends on the vintage of the block you're using....80's and 90's blocks aren't cast as thick as the 60's and 70's blocks. The older blocks can be bored quite a bit. I have a D9 (1979) block...and it's bored .060" over. No problems.
As with any stroker, piston travel is increased. This could cause premature ring wear...but I'd say you'd really have to put the miles on the engine to see it. Also, with radical stroker kits, the rods are so long and the piston compression heights are so short, that the
oil ring is moved to fit around the wrist pin bore. You can usually get around this (I did with a 425ci stroker)...but sometimes you can't help it.
The pro's? Gobs and gobs of horsepower and torque. There is no replacement for displacement.
The con's? I myself can't really find any on an engine that is to be used in a weekend car. If you install this in your everyday driver, it would be extreme. But these cars are toys.
Some of the engine builders even offer these engines with fuel injection. I'd say they're very reliable and tame.
Now you mentioned the 393's, 408's, and 418's. What you're dealing with there is a stroker with a little shorter rod than a 427W. What that brings is a higher peak horsepower....they like to rev a little. My 425ci engine peaked at 5400 with the torque peaking at 4500. So you're getting some of that increased piston speed back by the fact that you really don't have to rev it to get the power out of it.
Hope this helps.