If you search my name on rv.net and also on this forum in the tips and tricks section, I talk a lot about this subject matter.
You did everything right, but not everything complete. You complain of the floaties which requires continuous steering compensation. You need to get a front wheel alignment and a heavy duty front steering stabilizer. The brand we upgraded to is a Safe-T-Plus, but there are other good brands available.
Here is what we had done to our 2007 Ford E350 chassis with a PC-2350 on it's back. The motor home had only 800 miles on it at the time.
- rear heavy duty Roadmaster sway bar (the 2007 Ford E350 chassis had none to begin with)
- front heavy duty Roadmaster sway bar (the stock Ford bar is very thin and ineffective for the application)
- Koni-RV adjustable shocks set to the stiffest setting
- rear Hendersen trac bar (eliminates side-to-side horizontal tail wagging, especially beneficial when towing)
- heavy duty Safe-T-Plus steering stabilizer
- front wheel alignment
Cost $3900 and was definitely worth the expense.
Our 2007 2350 handles like a dream. No more rocking, swaying, unintended lane changes, or excessive steering compensation. I hold the wheel steady with a light touch and the RV stays put. Even under abnormal conditions, the RV handles well. I can even hold a cup of coffee steady, until I have finished drinking it. The safety factor is huge and means so much to me. Driving went from being a chore to a pleasure. No more premature driver fatique. The quality of ride to the passengers is an additional benefit. My wife will sit at the dinette and her refreshment will stay on the table. Her coffee doesn't slosh out from her cup either. Keep in mind, this is all while towing a vehicle.
If you think another brand of motor home would avoid this expense, it just becomes amplified as the motor home gets bigger. The bigger they are, the worse the problem. That is why people say the Phoenix Cruiser is better. Smaller is better, but still not right. It depends on where you are coming from, which would explain why the article written mentioned how good it handled.
I mentioned this a few times to Kermt. Phoenix USA should offer a "Handling Package" as an option or upgrade. They could easily install these upgrades at the factory and make some money from it too. The exception would be the front wheel alignment. That needs to be done with the RV complete and loaded. Just imagine people in RV forums saying things like "WOW, this thing handles great with that handling package option". One more reason to order a PC.