Shouldn't be a problem using them both, as long as you're happy with sag and rebound. Seems some like straight rate springs with intiminators. Racetech lists .887 spring rate for 190lbs. H-D spring rate is .350. With intiminators and stock springs, I don't get enough rider sag or travel. Brian, at Ricor is very helpful.
honestly, I don't have enough experience on a motorcycle to give a good critique, but my front end feels good, very solid and stable, tracks well, eats bumps (though I felt a bit squirrelly one night when I can upon a stretch or road that had been ripped up
for repaving suddenly at about 70, I'm sure it would have been worse if my front end were stock.)
Added a set of Pirelli Night Dragon tires a couple weeks ago, and put a superbrace on yesterday (not that I felt like my front end needed much improvement at this point, but it was on my list and I figure it can't hurt, right?) My front end should be about as good as you can get with the stock sportster forks.
The biggest challenge now is trusting my own work. I'm not yet fully convinced that my front wheel isn't going to fly off at any moment.