I've been using AvantGo for a while, thought I'd try Plucker... Getting it running wasn't very intuitive or Mac-like, but overall it's a great app. Some key differences that I've noticed so far...

On your Palm, the AvantGo browser takes over 2mb of memory. Plucker takes about .5mb. On a Z22 with no memory expansion available, this matters.

AvantGo only lets you have so much space used for your subscriptions (unless you pay) because it goes through their servers, etc. Plucker snatches stuff with its desktop software, no third party involved - unlimited channels. This is also important for people who don't want a third party seeing what websites they're visiting.

Setting up channels in AvantGo is a breeze. Even if they don't directly support a channel, adding an RSS channel is just as easy. Things are a bit more complicated in Plucker, but at the same time, things are way more customizable.

With Plucker, you have to run the Plucker desktop software (hideous UI - Java, I assume) and then have it update your channels before you synch with your Palm. AvantGo's conduit grabs the content when you synch. I almost prefer the AvantGo method because it's simpler and requires running one less program... It 'just works.' However, when I just want to synch up my calendar quickly before running to class, I have to wait an eternity for AvantGo to synch. With Plucker, either I've already grabbed the content or I haven't, and I don't have to wait for it to grab on the spot.

Minor thing - Plucker just directly calls up curl, which means adding a rule to the outgoing firewall (GlowWorm or Little Snitch) for every address you want to snatch... Whereas if it handled this such that the application 'Plucker' was trying to get out, I could just allow all :80 from Plucker.

Oh, and on the Palm side, the Plucker browser is much nicer, quicker, and more customizable.

So that's my experience in a nutshell. If you use AvantGo, Plucker is definitely worth giving a try.