Modo is a great modeler, that is a fact (as far as I am concerned) and it has become the tool I first turn to for any modeling and UVing needs. As someone has said, the only way to get modo away from me is to pry it from my cold, dead fingers!
However, modo is not perfect! Depending on your PC or MAC set up (and, yes, there is a version of modo for both and you get both when you buy the one!) modo can crash a lot. Some people experience frequent crashes. Others hardly experience a crash. Because of this, I highly recommend getting the demo and giving it a good workout before purchasing it.
Modo can be a bit unorthodox depending on which modeler you have used before. Frank finds it so intuitive because of his Lightwave background (I would assume). The developers of modo had worked for Lightwave at one time and so we see that many ideas from Lightwave made it into modo. In fact, modo was sort of presented (at one time) as the modeler that Lightwave's modeler was supposed to be. But if you come from using a program like 3D Studio MAX, then you may be initially frustrated. For example, the concept of having to drop a tool can make you feel like you are pressing way to many buttons to get a simple task done. I happen to like the modo work flow, but others may find it initially a problem.
3D painting in modo is great and is a lot of fun. However, it is not as full featured as painting in Photoshop or Gimp, so you will still need those tools from time to time. Modo is lacking a painting layering system like Photoshop has and this is essential for decent painting. You can paint on multiple images, but you cannot create layers for the one image (as in Photoshop/Gimp) to help control what you are doing while painting or to combine layers to get affects such as multiply, screen, etc. You do have these blending modes for your brushes, but no layers by which to apply these blending modes.
Modo's sculpting is fun, too. But it does not compare to ZBrush. ZBrush can obviously handle huge numbers of polygons as compared to modo. But with modo you get a traditional modeler and therefore you can move about as you are used to (i.e. you don't have to do things the funky way you have to in ZBrush). Modo sculpting can have some problems along seams, so it is good to be aware of that. Modo does offer some nice sculpting tools for both geometry sculpting and via using an image. General details are normally sculpted via geometry and fine details using an image. This way quality similar to ZBrush can be achieved.
One thing that bugs me about modo with both painting and sculpting is the number of steps you have to go through to get a brush up and running. You cannot just select the airbrush tool and paint, for example. You have to select an airbrush and then choose a brush (smooth, hard, procedural, etc) and you have to do this EVERY time you pick the tool up. In other words, there is no default setting for a brush (like there is in Photoshop) and so picking up a brush is not sufficient to paint. This extra click can get to you after awhile. True, it is only a click, but it has to be done each and every time you drop the tool and have to pick it back up again. Luxology should really set a default for any of the brushes and allow for modo to at least remember the last brush settings you had when you dropped the tool.
UV mapping is awesome and, for the most part, I have no complaint here. Are there tools that do it better? Some would say, "Yes!" and they have been bugging Luxology to further improve UV mapping. However, I much prefer modo's UV tools over the other big modelers (MAX, Maya, etc). One thing that Luxology did that was nice is that you don't have to learn an entire new set of tools to UV map. The move tool works for modeling and for UV mapping, as does scale and rotate. So if you know how to manipulate your model, you also know how to manipulate your UVs. There is very little extra to learn when it comes to UV mapping.
I could go on and on, but I just want to sum up by saying that modo, in my opinion, is a fantastic modeling tool. It is not Nirvana, but it looks like it is heading in that direction. Slowly Luxology is adding features. MaxF posted some shots with fur. Animation tools are slowly being integrated. Modo is evolving and this is great. However, the evolution of modo has been fairly slow. Even so, I cannot recommend this tool enough.
