It's all about the work ethic for artists. I think most of the professionals of the past produced a page a day. I remember reading that some of the artists of the 90's wasted most of their days playing video games instead of hitting that drawing board. Joe Mediarera of Battle Chasers was one of those dudes.
When Charest was hired to work on the Metabaron saga with Jodorowsky, he moved to France. There, I got the opportunity to meet him and see him work. So from those experiences, I can tell you that he wasn't a slow artist, just one with the highest standards regarding his work : few superhero comic book artists saw the quality of their work grow as fast as Charest did, when you llok at those early Darkstar/Hulk/Flash comics he did and where he was at by WildCATS #25 (his seventh issue IIRC), it is just mesmerazing. And when you look at his last regular WildCATS issue and the X-Men/WildCats oneshot, it again showcases giant leaps.
Charest was an artist who had/has studied fine art and illustration while becoming a mainstream comic book artist, and he got hungry for excellence. He was torn by te dichotomy between his commercial work and te ideals of fine illustration. While working on the Metabarons, he accounted several thousand pages thrown in the dustbins, many fully inked and hand colored by himself. I saw a handfull of those and believe me, those would have made any number one selling comi book editor supremly happy.
In the end, he never even managed to finish that graphic novel by himself as he got lost in the process, and I must confess that the coloring choices he made on the ones that made the cut showcased a few problems, the major one being a lack of timelessness : it looked like a Heavy Metal french SF comics from the seventies instead of a work of the future, at least on the coloring side of things. The technique was more then fine, but it served a flawed purpose.
Charest consecutivly went into severe depression, and has had many issues returning to comics. He did his one pannel serial Space Girl in a quite spontaneous way, but that didn't really go anywhere.
I don't know where he now is and what he works on, but appart from a handfull variant covers for Marvel and Image (the most recent being 2 years old), those old DH Star Wars covers, a 1 page story with Brubaker on Captain AMerica, he's been missing from our four walls little world and his site hasn't been updated for years.
So those are the last pieces of his published art to have graced us :
His twiter has seen half a dozen posts since the begining of the year though, featuring a Star Wars piece and some pencil work showcasing a somplified style, no info on what this was for.
I guess that if we were to ever see more sequential comic book work from him, that would be at Marvel, and with his Star Wars obsession, That could be a GN, but I wouldn't count on any annoucement before the whole damn thing was done and ready...
