First of all, I think it is in bad taste to charge for pre-release versions, especially without any guarantee of a final version coming out. Despite that Crikey is a pretty well-put together IRC client. There are a couple of things that need to be done though:

1. Use more Mac-standard style interface elements like the tabs, menu shortcuts and things like that.
2. The menus need to be reworked to be a little easier to use, not everything needs to be in a submenu, servers should be editable from the servers menus.
3. The friends and dcc transfer windows don't update correctly.
4. Add key commands to shift between tabs

Although this is a list of problems, I think that Crikey looks really great and may draw me away from iRC when it is polished a bit more.