Wow, I was fortunate enough to find a Heavy Wookiee Gunner today... what a figure.
I remember when I first got the Preview Wookiee, I was blown out of the water with how cool it was; how big, articualted and well sculpted.
Well, I think Hasbro may have done an even better job on the Gunner Wookiee. The basic body is exactly the same, but the paint job on this one is excellent... and the shirt thing is very well done. It's kind of like a leather material, and fits him well.
To me, the first one had better accessories, but this one just looks better as a stand-alone figure. It could be "at home" in a number of dioramas too. He could be a regular Wookiee farmer, a traveler, a bar patron, or a warrior.
I'll try and take a comparison pic of the two tonight. If you liked the Preview Wookiee, then this should be an excellent addition to your collection.