You posted a question which asked "why isn't it free?" earlier; simply, mIRC use to be free. It was once a hobby, but since the author, Khaled, found an actual LIFE outside of the bliss of writing mIRC (lol), and never expected it to grow so large, he wanted to quit writing it all together. Well, the idea of 'support' and a 'registration' came up, and it jingled his jangle quite well (to put it frank). Long story short, mIRC is now SHAREWARE. It's great to register mIRC because it will make Khaled feel all warm inside (actuality, if you enjoy the application, it's best to register it because you support it and the author appreciates the gesture).
Using mIRC non-stop 24/7, with all of it's great features, makes it more than worth the registration fee that you choose.
Now, to answer your next question: The real advantages within registering your copy of mIRC reflect mIRC's future. When you register, you are voicing your support to Khaled in order for him to use much more time to keep releasing newer, and better, versions of mIRC. This is a good thing, trust me. Glad to hear you decided to register!
The guarantees which are presented when registering mIRC do not include anti-K:lines or anti A:kills. These modes are set by IRC servers, and not mIRC itself. If you have been K:lined or A:killed you cannot and SHOULD NOT try to get around it. Most operators will permanently ban an ENTIRE host for avoiding bans on a server. Please know that there is MUCH A DIFFERENCE between an IRC Server (Such as: DALnet, UnderNET and EFnet) and an IRC Client (mIRC).
If you need a guarantee, well then, you can be guaranteed that Khaled will be as happy (if not more) to recieve your registration as he would to recieve a free visit to a vegetarian buffet.
In all hopes that I've given you some valuable (and exhaustingly lengthy) information, I say "Thank you for continuing to 'CONSIDER' registering mIRC." ;-)
