I had a 2010 CVO Convertible and traded for a 2013 CVO RK. I would have a couple points for comparison.
I really liked the Convertible and I really like the RK. But they are very different bikes in my opinion. You definitely sit much lower with the Convertible, you sit in the bike not on the bike. I even added a Corbin which probably brings you up a inch and you are still quite low. The Corbin along with a set of progressive shocks...and I found the bike to be very comfortable. And a different windscreen. The major differences in my view:
1. Handling. Between the rake and I suppose the rear tire as well, I found you have to work much hard in the curves than with the RK. Curves are effortless on the RK.
2. Braking. The RK has much better braking, two discs up front make the different I assume.
3. Vibration. The Convertible is very smooth at idle and up to the 50-60 mph range. Beyond than you get a pretty good buzz, whereas with the RK...as you know...it is very smooth way past 60.
4. Lighting. The Convertible lighting is not particularly effective. Of course I had to add passing lights to the RK, so this might just be my need to see and be seen.
5. Weight. They don't vary that much on the books but moving the Convertible around the garage was so much easier than the RK. I generally kept the bags off so maybe that made some difference. That is another minor point, removing the bags is a really nice feature as it results in such a clean rearend. And you can easily access the rear wheel for cleaning and checking tire pressure. With the RK, as you know, you basically have to remove a saddlebag to access the rear wheel.
I added a Corbin to the RK also. Again that raises one a bit so that would not be an option unless you had it customized. Good luck on making something work.