The LP business model is one that most online retailers attempt to emulate. Good prices, fast shipping, reasonable customer service and fair policies. Where LP differs is that they don't like the manufactures authorized dealer policies in the areas of MAP, and likely things like purchase quantity restrictions. It's somewhat of a mystery how exactly they get the quantity and selection of products they carry, but it's obvious that they are dealing directly with either the manufacture, or large wholesalers to maintain their inventory even if every manufacture denies this.
I like LP, they are a huge reason there is competitive pricing in the retail scuba industry. However if you want the best of both worlds, I'd second the recommendation for ScubaToys. They match LP pricing, and they are authorized dealers for everything they sell.
To answer your question, I'd purchase ANY scuba item from LP without hesitation. Very few products come with a warranty that is so good that it's going to save much over time. There are a few exceptions, but for those types of items, and really most anything else ScubaToys is hard to beat. I do try and spend some bucks at the LDS as well. This has become increasingly difficult as they just don't compete in retail well, and feed mainly off the new divers for personal gear. But I generally shop the LDS first, and then go online.
