I have both on my hunting guns. The Red Dot is faster and easier to align with the target because eye reticule alignment isn't a big deal like with a scope (something about parallax). I have a Bushnell Trophy 1X30 with four sights pictures about $90, a Readfield same setup about $275 and a ECT Tec Tactical Holo sight about $400 of the three the Bushnell is the only one to really be put to the recoil test. It is mounted on a 12 inch .411JDJ (full length .444Marlin necked to .41) Contender. No problems after 50 rounds of some heavy stuff.
I also have many scopes since all my guns have some kind of glass on it but two (old, bad eyes). I have just about all the major players in the scope field. The two I like best are Leupold and Ziess. I dont have a Swarovski so I cant say about that brand. Of all the scopes I use the low power 1.5X, 2X, and 2.5X offer the fastest target alignment and more than enough power out to revolver ranges.
The bottom line is like with everything else get the best you can afford; maybe save for awhile to get a quality optic. Buy a quality mounting system and if you dont feel that you can do a correct job of mounting your sight bring it to someone who can. Ask and many here will readily offer that they have, many times, as much invested in scope and mount as in the gun.
No matter how good the gun and shooter you still cant hit the target if you cant see it or worse yet hit it someplace where you dont intend to.
