I'm gonna have to disagree with you. How many years spent penciling and the dude still can't draw the following:
-thumbs
-feet
-faces without ridiculous expression lines
-proportions
-backgrounds
-things in perspective
-realistic weaponry
Plus the man can't even maintain continuity petween panels on a single page. As for the costumes and accessories for the original X-Force team? Cheesy and uninspired, not to mention not particularly rooted in believable reality.
What the heck were all those stupid belts, straps, weapons, pouches, goggles, etc. for? All right, I'll concede that other artists were doing similar things at the time. Jim Lee for example did similar things to the X-Men of the same time. At least his characters' look was consistant from panel to panel and still maintained a sleek functional design. I can recall, without even having to go look through my back issues, a particular issue of X-Force where Mr. Leifeld had decided to redo the look of Cable's bionic arm. In the span of 3 or 4 pages, he declared the new arm in the dialogue text, drawn the new design, within three panels got bored of drawing it the new way and went back to the old version, obviously forgot which of Cable's arms was the bionic one because it switched arms and back again all the while the number of silly pouches or what type of said pouches he has and how many belts he's wearing.
The only reason this guy's crappy art was accepted, was that Todd McFarlane had a similar cartoony style, that was really revolutionary, while doing Spider-man. When Leifeld first got popular and did a few guest artist stints prior to getting the New Mutants assignment, McFarlane was inking his pencils and clearly fixing Rob's goofs. I think this was made his art more paletable at first. It sure fooled me early on. When the NM rebooted to X-Force Rob started doing his own inks and that was where it hit the fan.
As for the costume designs? Well they kinda worked but then every character, hero and villain, would start sporting similar designs. Unless they were just nameless soldier types, in those cases Rob was invariably lazy and just drew in amorphous, vaguely humanoid forms. Things like Shatterstar's headgear? Why? It's ugly and again Leifeld fails to maintain any continuity in it's size and look. It and the other similar headgear modeled by every second other character were there simply to cover up Rob's laziness to draw more faces and to help make the poorly drawn ones of other characters more easily identifiable.
Best thing that ever happened to X-force was Rob Leifeld leaving marvel. For further proof, just look at the rip off characters he created for his image teams. I could draw better than that tool when I was twelve. After he got fired from the company he helped found, I am baffled that he has found work since.
End of rant.