I used the Hy-Road last season and picked up the Nomad PEARL few weeks back. I needed a pearl in my bag, had a solid and hybrid.
I found for me the Hy-Road was more of an arc ball with a very smooth transition down lane. I could easily belly the ball out and back to the pocket. The core rev'd up easy enough, better then most. My wife throws this ball now and plays it straight up 7 and it makes one wicked jump off the dry for her. So it is a very versatile ball.
Now the Nomad PEARL is something else. The core is as poster above said DYNAMIC!! I put this ball out and it comes roaring back. I bought this ball to be my go to ball as the lanes dried up. Its found its way to my benchmark ball after one week. The core seems to rev harder after it flips!! Now from what I have heard the only difference is the SOLID is about 2-3 boards stronger and reacts a bit earlier.
In my opinion I would say it depends on what you are looking for. Are you looking for a ball to play "similar" lines as your Virtuals or something to be able to move and play a different line? The Virtual balls we have drilled in shop and I have seen thrown are "longer" snap balls. They look a lot like the breakpoint shape from the nomads. So I would suggest Nomad to compliment the 2 you have. HOWEVER, if your looking for a ball to do something DIFFERENT from what you see from the Virtuals, then its the Hy-Road.
It honestly is all dependant on what YOU want from the 3rd ball. Some people like to have balls that play similar breakpoints so they can just switch to the "next" ball as lanes start to go away. I also know people who like to "JUMP" when the lanes transition and play a whole new part with a different hook shape.
IF I had to choose.....I would PERSONALLY go Nomad. I have my solid on order I love the PEARL so much. The Hy-Road gave me some nice games last season, but made its way to back of bag and eventually out. Now as I said earlier the wife has it and loves it. To each his own I guess.