Yes, I have the 3". Its a good quality kit. Only have a few choices to get more comfortable on the bike if your taller. This is the least expensive and looks factory still.
I have the 3" extensions on my Mastiff and LOVE THEM! Awesome riding position as a result and they are solid as a rock. Best functional mod to the bike so far.
I'm 6'1" with a 34 inseam. 3" is perfect, any longer and I wouldnt be able to rest my ankle on the foot pegs when my leg is straight. The inseam(length of your legs) is the magic number. Obviously, if you have a 36" inseam you can go with 5" extensions.
Depends on your riding style. I am 6'4, around town I like to ride with my feet on the pegs with my legs somewhat extended but when I'm on the freeway I prefer to have my feet out over the pegs so I have the 5" extensions. If you ride with your feet on the pegs all the time and don't want your legs extended to far go with the 3" kit. You won't find a better product for BigDogs, if you need an extension, and Doug at DMC is a great guy that will take care of you.
The quality is fine. Its basically longer extension plates than the factory ones and the shifter rod has an extension. The brake line might need to be extended depending on which bike and how big you go with the extension. If you have basic mechanical skills its an easy installation. Few hours. I did mine in 2 hours. Bleeding the rear brake takes the longest time. The kit comes with all the hardware needed and good instructions. I was cramped on the bike before I put them on. It's absolutely perfect now
I had Doug design a 4" extension for my 2010 Bulldog. It's a great mod with the foot boards as I can place my feet where we want at the time. Doug will design and make a top quality product hands down. Call him and tell him what you want.