I'm trying to get some creative sculpting software and wonder which one would you recommend for product design and ideation and why - MODO, ZBRUSH OR MUDBOX. I'm using Cintiq touch so UI aspect also matters to me.
Modo - can do everything and has a great renderer. A lot of product designers use modo. Modo sculpting is inferior to mudbox and zbrush but it can do basic stuff. I like to use it while modelling.
Zbrush - sculpting only, their BPR (renderer) is not so great compared to a dedicated 3d rendering software like modo. Zbrush will run well on older systems too.
Mudbox - You cannot run mudbox standalone, unlike zbrush, you need a base mesh to import into it first. Mudbox has better texturing than zbrush's polypaint but their sculpting tools are no where near Zbrush's tools.
Every one of these have a good UI and modo/zbrush can be 100% customized in the UI aspect. I have been using modo since 401 and really enjoy using it along with cinema 4d (which also has sculpting but about modo's level). I use zbrush sometimes but I am more into graphic design instead of creating 3d assets so it doesn't call for my attention often. Zbrush is always making massive updates and always free too. Pixologic think of amazing features to add and leave mudbox sculpting behind further every release.
If I were you and had to choose only one software, it would be modo. Reason is, modo can do everything, zbrush can't. Product design calls for accuracy and modo has that. Zbrush is very organic, eg no dimensions or specific radius on corners etc.
Modo has become a very popular software for modelling and rendering. It has one of the most robust render engines to date also. It is quite easy and enjoyable to learn. I suggest you take a trial of every software before laying down any money though. A lot of my influence is personal preference.