I have been an avid LightZone user until its demise.
I still have it and continue to use it (for unfinished projects) thanks to some knowledgeable friends who do their best to keep it alive... sort of!
That project is called LightZombie, by the way
I was keeping an eye on Bibble's promised 5th version and now I am a user of AFP.
- The Linux support is great. (See my earlier post on packages for Arch Linux).
- The speed is simply unbelievable. (This was one of weakest points of LZ).
- Layer funcionality is very good. (I still believe the implementation in LZ was better especially for the first timers; almost all the tools came with innumerable layers. There was no need to specifically create a layer or a layer mask etc).
- Complete workflow is good (especially at this price point).
- The concept of plugins as "natural parts of the workflow" is good. I hope more plugins become available soon.
- Customizable keyboard shortcuts are nice.
I can continue ad nauseam!
In short : I like using (and playing with) AFP.