i agree mostly with the dependability at staying stock.
However, I have 50,000 miles on my Ultra with upgraded cams. Still runs like new.
The most important factor, this is me thinking-not saying I am right or wrong, is who does the work, what changes your making, how hard you are on the engine. Harleys have a long stroke so you can cut dependability quick by using high rpms. With the run out on the cranks specs now a lot of high rpm's would concern me.
I have the ss 106 kit, including cams. I bought it that way and not sure what cams they installed. I can say it is very very strong, Torque is way up there. According to the dealer I got it from it pulled 96 hp with 110 torque. The lope of the cams gets everyone's attention.
This is not my daily rider, it's my girl friend and my knock around ride.
If you do decide to change cams have the run out checked. HD specs are no where as tight as they use to be.
Oh, I have been using a PCV with auto tune on my ultra for over 30,000 miles and I love it. The Dyna has a canned map that seems good.

Just a thought.

 

Agree w/most - stick to the basics (air, exhaust & tuner). Lots of good ones out there & huge # of members use Fuel Moto. I like to be different & went w/Dobeck tuner, LA Choppers breather & Bub-7 TD's...bike runs great & enjoying the fruits of my labor...good luck w/your decision(s).