So far, based only on highway/city driving, very positive.
My poor-man's description:
I'd say it is 'crisp' instead of firm, stiff, or rigid as I have heard others describe it. It may just be semantics, but I feel that 'crisp' is a better, more positive reflection of the ride behavior I have seen so far.
Before the OME, the stock suspension still rode like a truck, but was also 'squishy' with body roll & lean through corners. It also seemed to hop a little more with the stock suspension, whether over washboards or irregular asphalt conditions. Nothing terrible mind you, just typical of a body-on-frame ride that I'm used from F150s and similar.
Now it rides much better, feels more stable, and I would definitely NOT have anything negative to associate with any increase in 'crispness' of the ride. Haven't had any 'hopping' to report in my <24 hrs of driving, but the ride from central Denver to Tech Center as notably enhanced with the OME upgrade. (OME can't fix traffic, however

)
Still have yet to take it into the Rockies, but I expect improved characteristics there as well (as attributed to countless others already about the OME offroad improvements). I'm also expecting a much greater ride under load, and I expect to find that out in a few weeks for an upcoming ski trip with several adults, gear, and luggage.
In short, it seems that the OME suspension upgrade is something that I will certainly do if/when I have another future LC, and next time I won't wait as long to do it.
Hope this helps!