The biggest thing from going Keyclone to IS Boxer for me, was the difference between Keymaps and Repeater.
I'd imagine the same thing will apply to Pwnboxer to IS Boxer, too.

Repeater is straight broadcasting.
When you push "A" on the keyboard, all the others also receive "A".
So this is like the keys which are broadcast in PB, but it is everything including the mouse.
One of the examples in my IS Boxer Guide (see signature) is separating Key and Mouse repeater into two mapped keys.

Key Maps are groups of Mapped Keys.
At a basic level, most have a hotkey to activate.
And they do something.
Most of your previous PB hotkeys, where you push "1" and it broadcasts "1", you will want to convert into Mapped Keys.
Note: The wizard generates a bunch of mapped keys for you, notably 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, -, = are all FTL DPS Keys.
Which means if you put Fire Ball on "1" on a two Mages, Frost Bolt also on "1" on a third mage, Shadowbolt on "1" on the Warlock... and press "1" from any window, without any warcraft macros they will all assist the active window and cast whatever is on "1".



You can separately toggle on/off both Keymaps and Repeater.
If both Repeater and Keymaps are on, Keymaps take precedence -- meaning if you have the key T set to send the Lifetap keybind to your Warlock windows, pressing T will do that rather than send T to all windows.

When you're entering your password, you want Keymaps Off and Repeater On.
In the game when playing, 90% of the time you want Keymaps On and Repeater Off.
When chatting with a friend or in trade, you want Keymaps Off and Repeater Off.
When playing and you want everyone to click a portal or to select talents (same class/spec) at once, have both Keymaps and Repeater on.



The IRC is a strong resource, as there are people there 24/7.
Basically enter it, ask your question -- not ask if anyone is there.
Then wait...
If there's no immediate response, don't leave the IRC, it is just a browser tab.
Check back in a while.

The IS Boxer forums are a great place for support too.
Lax checks those several times a day; anytime I have a question it is answered quickly.

If the question is more generic or game related, and less of a technical question...
These forums rock, as there are a lot of users here every day (more so on weekdays).
And players have adapted IS Boxer's tools to their game.