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See THIS thread. Short answer: Ultradot matchdot.
If it's going to be used for competition, the tube type is faster on target and still works as a sighting device even if it fails.
For plinking, it matters less.
Although, until you get used to a dot sight, the dot can be hard to find.
Unless the gun is well pointed to the target, the dot has a tendency to disappear off screen.
So, in the final analysis, get the one that is easiest for you to use.
And, in bright daylight, green is easier to see than red for most folks.
thank you.