Yes I agree Sedated. Ubuntu is really the best distro to start with for someone new to linux. I have been playing around with it for some time now and have found it amazing easy to install every tool we hackers normally use. One thing to be careful with a disto like this is all the upgrades they make easy for you.  If you have your version working perfect with all your tools there is no reason to upgrade.  I had people in the past get mad at me because I recommended Ubuntu and they worked very hard to get all their tools to work like aircrack-ng and kismet, etc...  Then they would do all the upgrades to the new version and found they no longer work!

Many upgrades are security orientated and that should not be a concern for a pentester. To be honest, my version of linux has so many holes in it when I am pentesting I should call it swiss cheese linux!  I think you will find the more open it is the easier you will get results. Now dont get me wrong, for my day to day working I use a very secure set up. But when I am pentesting I boot to what I call my "holy" version because of its vulnerability. I dont run a firewall, etc...  Remember the more security the less flexible your OS is going to be.  If you have been having problems with exploits, etc.. perhaps you have locked down your OS too much?

But dont I assume some risk? Well perhaps, but I have been hacking a long time and to this date ( knock on wood) I have never had some one own me while I am doing a pentest.  Now I do take some precaution. I am very aware of any connection to me and if I upload data from a compromised server I do it to a very secure situation in order to protect the company I might be working for.  I always work with 2 boxes at the same time and I dont record my results on my open system. Not even a simple record of my nmap.  I hope you get the picture. Attack with a very open and flexible OS, but record in such a way that nothing gets compromised. Could you imagine how much it would suck to be doing a pentest only to open a door for a script kiddie! Careless pentesters have done this in the past so be careful.