I have both and can't add much to what has been said but the rubber mounted motor is way more comfortaled on the highway than the solid mount balanced motor. I think someone previously advised that if you ride mostly in town, the softail is the ticket but if you tour or spend much time on the highways and byways at cruise speeds, the rubber mount is the ticket. I think that is good advice.

The rubber mounted motors don't vibrate; the engines shake at idle but smoot out about 1500 rpms and or solid smooth at 3000. The softails vibrate and the vibration will sneak up on you after about 50 miles or so. You will start to feel some numbness in your hands; I ever feel the vibration from my Deuce through my feet. ISO grips or something similar will help with the hands and a gel pad or a good seat will help with the numbness in the butt but you can't escape it on a 500-600 mile day.

 

I have had all, the dyna I had would vibrate at all speeds, Touring bikes vibrated/shake at idle and are smooth once moving, the softail is smooth at most speeds except about 65+mph then you get a constant vibration through the whole bike like a dyna.
The dyna's vibrate/shake the most of any bike i've ridden, that is why they come with those "special" and ugly extra thick rubber pegs...

 

I haven't put serious miles on my Fat Boy Lo yet but compared to my Dyna I actually prefer the feel of the Dyna more. The only vibration I ever felt on the Dyna was when sitting at idle but as soon as you took off it was smooth like silk. With my Fat Boy Lo it seems like I feel the counterbalancer working. I don't know if that is because my bike is still being broke in but I find it more annoying than the vibration on the rubber mounted Dyna. Yesterday I went on my first 100+ mile ride on the Lo and man was I fatigued when I got home. I don't ever remember feeling that way with the Dyna on such a ride.

 

Funny how Harley guys piuck on metrics for lacking "soul" (whatever THAT means) and being too smooth, then want their Harley to be smooth........ Just sayin..... If the motor was too smooth, I'd just as soon have a VTX. I like to feel the engine.

 

Drove a 09 Heritage last weekend...nice and smoooove until you get to about 60MPH then you feel that the motor isn't rubber mounted...can't wait to get my FLHTC back this weekend.....

 

I currently own both - '06 Street Bob & '10 Heritage. The trade-off seems to be more vibration and low-end torque on the Dyna vs smoother ride and blur-free mirrors on the Softail.

Some days I ride the Dyna because I want that low end torque and better lean angles. Other days I ride the Softail because I want the smoother ride and more comfortable (stock) suspension.

 

the touring motors only vibrate at idle.. and nothing even close to my shovelhead.. at 20 and up it is smooth and at highway speeds it is like a glider.. no vibes or sound even if you have stock mufflers on

 

Depends on what you like. I have a rubber mount engine and I like...make that love the engine vibration at idle. That engine is shaking and I feel alive. Some people like the smoother engine. Whatever floats yer boat.