It seems there is quite a split of opinion on the use of kata.. so my question is what styles of martial arts do not use Kata?

maybe this can help me understand peoples opinions better..?

I think it depends what you call kata. In its traditional sense, solo movements that CAN replicate fighting, Aikido, Aiki-Jujutsu, Judo and Jujutsu have no solo forms per say. They do have 2 man forms that could be considered kata. Most all the Karate or striking arts I have found have some form/kata/hyung in their curriculum. It seems that most grappling do not have solo kata. This doesn not take into consideration eccletic styles that may have included both. I know of Kempo Jujutsu styles that have both forms and Grappling. I think locking and grappling may not lend itself to forms, yet, Torite Jutsu is a good example of the locking, throwing arts of kata. We study a Eagle Claw Chin Na system that is a 2 man form. This is kata in my eyes, however others may see it more like Ippons. Ippons however in my mind can be kata as well, just short versions. But then I see and group of movements as kata. In Kempo, I see techniques like 5 swords and dance of death as forms, string 3 or 4 techniques together and I think you have kata.
Another style I study that has no kata is Sambo, Russia's version of Brazillian Jujutsu, and San Jitsu also only has 1 form in it that resembles traditonal kata.

Senseilou is correct but it also depends on your definition of martial art. As Senseilou notes the distinction between grappling and striking arts is informative here. Other important distinctions might be new/old and armed/unarmed. Many 'new' arts avoid kata (but use ippon or set sparring) largely because they are ecclectic arts that strive for a complete striking and grappling base. I would include jeet kune do in the 'new' catagory for this reason. Armed martial arts lend themselves well to solo collection of movements or katas. As far as i have seen unarmed European arts (pankras, wrestling, savate)do not use kata. It is importan to remeber that 'martial art' is not a title only reserved for close quater fighting systems of the orient. Once this is acknowledged it is much easier to understand the differences of opinion on training kata an forms. There is also the reality that grappling arts that do not lend themselves well to kata have proven to be some of the most effective ways of stopping an opponent.