I think it's worth it. Sound quality is still great as is CPU efficiency. They've added some new distortions types, new filters, etc. However, and this may sound a bit silly, but the interface was one of the key selling points. Aside from being sleek and graphic heavy (versus copy/text heavy), right clicking on any of the main filter parameter brings up a nice looking visual menu (see below) that's intuitive and very easy on the eyes. It's little things like that which I can appreciate, even if they are a bit mundane. The vowel filters still sound ace and all the distortion types vary in flavor (transparent to destruction).
I would encourage anyone interested to download the demo first. But all in all, I'm extremely happy with it.
I cant get over how accessible and user friendly massive is. The workflow is so much better than the other synths Ive mastered, and the wavetables and filters are top notch, and make up for the things it lacks. I'm also digging Logic's amp designer, which is sooo gooood for basses. Also, this little thing is just awesome. Sounds very subtle but sounds top notch.