I have 3 ariens and a new Holland. (the NH is actually the same machine except for paint)
Of the 4, only one has power steering. And 2 are GT 19's and of them all only one GT19 has power steering. And I noticed the difference with the PS especially with the snow blower on the front.
And I do notice the difference with the mower decks mounted. But my wife has run all 4 at one point or another with the mower deck mounted. And strangely she says she doesn't notice anything different between them, while mowing between one with PS and the 3 without. I wasn't gonna say anything about the difference between them to her but after having her run the one with PS a couple of times, and then the next time I put her on one without, and she didn't complain, so I had to ask her if she noticed anything different than the other one, and she even said she didn't. Which surprised me. But if she doesn't notice I'm not gonna push the issue.
I've had that machine 4-5 years and til this spring I never took the blower off/ but I needed to use it with a mower deck this year, so I had to take the blower off.
Power steering is over rated on a GT unless you run something front heavy, like a snow blower or a bucket.