This is my Arch:

And I can't show my slackware 'cause I have no DE nor WM :)

@sysman in my opinion there are no client on Mac, Linux or BSD which beats Outlook do to there exchange implementation.
But I will say Thunderbird has come a long way, I would say. What is it you are missing in Thunderbird?

MacBook Pro Fall 08 Unibody
2.8GHz Intel Core2Duo
8GB 1067 Mhz DDR3 Kingston RAM
NVIDIA GeForce 9400M 256 mb and another I don't recall
Seagate 750GB Momemtus XT Hybrid disk
Opertaing systems: Fedora 17 (Virtual) using Gnome - OpenSUSE 12.2 (Virtual) using XFCE - Windows 7 (Virtual) - Mac OS X Server 10.7.5

Fujitsu Simens Amlio M1425 (very little info do to the fact I have lost the info)
1.8GHz Centrino m
512MB DDR2 RAM
ATI Radon Mobilty 9700 125 MB
80GB HDD
Operating susyems: Fedora 17 using OpenBox and SlackWare 13.37 using XFCE

I would recommend either ArchBang or CrunchBang very very lightweight and in my opinion they are very easy to use

I am not all new to linux, I been using linux on and off since 2006.
Besides that I am currently studying for an AP. Degree in computer Sciences and I am from the mighty country Denmark ^_^