I see I'm a bit late to your question, and I only found it by "asking the same question", I too love my Whirlwind it's my favorite machine!
I also own Road Show most recently (i'm loving it!!), Whitewater which I saw you already owned (crazy fast and furious at times!), and Tales of Arabian Nights, (smooth and seems controllable compared to lots)
I've played many many other machines over the years as well. The thing most people don't like about Whirlwind is the reason I love it, it's simple but difficult. My high score is 26 mill.
I seriously doubt there's a comparable game...to me they all have differences. Yes there's machines that copy some of each others playfields, or rule sets, but most all of them seem to have something unique.
WHIRLWIND = best music throughout, love the jams when you post a high score!! Such a cool theme with awesome Youssi art work, LOVE the spinning discs and the top flipper shot is great!! I'm also a fan of JET BUMPERS and the six on here are placed so well, and are integral to it's design!!
"Ya all come back now!!"

For a pre-DMD game I find it hard to beat.

I've gotten real good with the timing on this shot, still miss it frequently, but have learned to nail it a lot too!