I have not used the hill rom for a couple of years now, since it was replaced by my inCourage. I don't know what the new hill rom vests look like, but i found them uncomfortable around my breasts, since the jacket is cut very low - and the jacket was too short. This probably isn't an issue for a 2 year old, though =). I also didn't feel like I was getting an adequate treatment with that system for some reason, I can't explain it exactly....
Respirtech actually custom fit me for a jacket so it covers my entire torso, because I'm so long waisted - I feel like I'm getting more coverage. It does NOT bother my mickey button at all! The hoses are SO much nicer than the hill rom I had - just the fact they clamp is great. I even was able to do my vest treatments right after my lobectomy it was so comfortable.
Customer service is nice and fast - they had a replacement machine to me the next day when mine stopped working and picked up the old one as well.
One thing I will say, while the vest is GREAT for convenience, I would NOT discount the positive benefits of manual hand chest PT. I still have my husband pound me once a day and I get SO much more up when he does it. Overall, I do not think the vests are as effective as manual chest PT, so I personally would not recommend trading one for the other. If I had one regret - it would be not doing as much manual chest PT because I feel it really is much better than the vest.
Good luck!