Hi muffincake and welcome to the site. I have had similar concerns as you. Firstly, transact won't work w/act 2005. I use act 6. Transact was just fixed so it works w/ppc 2003se, which is what your pda has, so that's good. If you can downgrade your act then you're ok. Another member whos name escapes me, loves transact. I tried it b/f they did the fix and found it unusable at the time.
Since then I got a palm tungsten T from my brother in law as a 2nd pda. On that I loaded act for palm os, which is ok. I'm sure transact is better.
See this thread for some more input. I'm dying for act on my ax, and companion link and act link are not acceptable. I am seriously considering transact. Meanwhile, I don't think your company will scale back to act 6.
I have a question for you. Did datebk5 sync w/act?
I found PI to be pretty good, but I didn't want to work w/outlook, so I unloaded it. If it worked w/act it would be a winner.
Let me know what you find.