You will love the Power Trac over the Steiner. I had a 430max Kubota and made an adapter to use walk behind Gravely attachments, mainly to use their rotary cutters (as Ventrac rough cut mower was close to $5k just for the attachment). The PT is hands down better for rough cut brush removal!!!!!
I use a PT180 with a PT rough cut rotary and a PT1430 with a Titan 60" hyd flail (mower was around $2500).
You could look for companies that posted online reviews of the PTs and give them a cold call to see if it is near time to update.