Both manufacturers make a very high quality wetsuit, and providing you get a good fit, you'll be happy for a long time with either one. Just keep in mind they use 2 very different patterns and sizing charts for their fit.
The Henderson suit will fit pretty true to the middle of it's sizing chart, while the Pinnacle suits tend to fit better toward the bottom of each size range. For example if it says the waist is for a 32"-36" the 32 and 33 fit very well, the 35 and 36 not so well.
When purchasing a suit using a sizing chart keep in mind that the height and waist measurements are going to be your most important. The suit needs to fit you correctly "around" in order to keep you warm. Height is a secondary measurement to most wetsuit manufacturers and they come up with it off a general chart. Basically in their estimation "most peope so big around were generally about yay tall". There's not a lot of science involved. And you can almost always toss the weight catagory out the window as they don't take into account that muscle being more dense than fat, 2 people can be the same size in inches but outweigh on another by as much as 20 or 25 pounds. That can mess things up just about every time. You'll also notice Pinnacle's sizing chart can tend to run a bit "tall" at times.
It's not to say that either has a bad or better approach. In fact, for me and any other sales person or instructor having 2 high quality companies such as these with 2 very different charts/patterns makes for great flexibility. If one manufacturer isn't fitting well, we know we have another to turn to that probably will.
