I just bought the McFarlane Maxx a couple weeks back, and I love it. Comic-accurate look and proportions, great paint, very nice detail, really shows his personality.. Sure, it only has 6 points of articulation, but it's The Maxx! His pose doesn't even change in the comics. He's either squatting or squat-running. My only complaint is that he's lightweight and obviously hollow. But I'm not going to play with him, so that's not a problem. He looks great displayed.
Don't buy from Shocker Toys. Even if their figures didn't suck, their business practices are reprehensible. Google them and see how much bullshit they pull. Complaining on message boards, downright insulting fans who make a single negative comment. Their figures are low quality, with terrible paint and design. Look at some of their figures, they all look like fucking birthday cake candles with that wax paint. They're the most downright unprofessional toy business I've ever seen. Look at that image. Terrible pose, far too saturated white, and a caption that just screams MS Paint work. And that's an official image from their site! They look like a bad eBay seller.
And their Maxx is really not that good if you look at him closely enough (with an eye towards comic-accuracy. I assume since you're interested your a fan of the comic, or cartoon). Sure, he's got double jointed knees, but not all figures need articulation, and Maxx is one of them. Why have double jointed knees if he's only accurate while posed crouching? His legs are way too skinny, and his feet are tiny, misshapen lumps of poo. His waist-to-chest ratio is downright Liefeldian, and his arms are way too long and inhumanly proportioned. Plus, look at that hideous paint. His knee joints are a completely different shade, and the whole thing is waxy and splotchy.