I have a couple of Ultra Dots in use and find them excellent in most every way. However, I have come to prefer the Match Dots for a choice in reticule size. My vision is considerably less than great and some days I need a larger dot and some days I like smaller.
The 30mm size has a larger field of view that is very helpful for a "field pistol".
Regarding batteries - I buy them online from "Battery Bob" and get a bunch of them at a time. The shipping is free and the price is MUCH lower than local prices. The service is first rate. Sooner or later you WILL leave it on and when you next check it the battery is dead. Buying in quantity solves that problem and costs little.
http://www.batterybob.com/product.asp?intProdID=101232
Here's an example of quantity vs price:
1 - 3.99 delivered
5 - 6.89 delivered (unit cost $1.38)
11 - 13.75 delivered (unit cost $1.25)
These are top line batteries - Maxell
No, I am not connected in any way - I just know a good thing when I see it...
Dale53