Sounds like an excelent plan to me
From what I've seen I'm a big fan of their capabilities, just not the seemingly long winded way to do what other devices handle very simply.
I was always planning on working through the online training after the Christmas / New Year madness subsided so you might be onto something, and once completed, I'm sure my mind would be rewired in a way not to find the procedures complicated in any way.
Just wouldn't have a device to practice with if we manage to shift this one.
NOTE:
As it turns out the port forwards may well have been working perfectly well all along.
the 33899 > 3389 redirect I couldn't get working didn't initially work on the new router either until the network card was restarted on the server (thinking a Winblows update for the card drivers knackered this as there was one applied the end of last week and no reboot since), and the sip issue was another matter.
Our provider was adament that it was setup correctly, as it was tested with a test number over sip whilst running our main system fed from our analogue PBX before migration, but it turns out that no matter what I tried it wouldn't have worked, as the old system only passed a 4 didgit number to the phones where the sip was passing 6 (so the phones didn't know what to do with the data), and whenever we dialed 9 for an outside line our sip pbx was trying to route the call via the old analogue pbx and not the sip provider.
The boss is rightfully fuming with them, and for my own sanity i'm going to hook the SRX up over the weekend to see if it now works!