I've ordered from LP for years. I've never had a bad experience. My experience is they've done more customer service than less.
Years ago I ordered a Mares Puck computer. It arrived and I opened the box to see it was the Puck Pro. I called them and told them they screwed up, that I ordered the Puck, not the Puck Pro, and that I'd just pay the difference I owed them. They guy pulled up my order and said, "Yeah I see a note here. We are out of the Mares Puck so we sent you the Puck Pro instead. You don't owe us any money."
Another time I waited for my order that I paid extra for 3-day delivery and after 5 days I called them to basically bitch. I was reminded one of those days was a federal holiday and the other was a sunday and the mail didn't move those days. I felt like an idiot but they cheerfully refunded my postage even after I told them never-mind, it was my error. I actually did receive my order in three "business" days.
On another occasion I had a computer I was selling them on their "gear buyback program". The gentleman quoted me $125 after I sent him photos and told him it was still like new in the box and had about 12 dives on it.
A few days later I emailed and told them I was mailing it. An employee replied and said when they received it, they would check it out and tell me how much they would pay for it and if I didn't like their offer, they'd send it back to me. I told him I already had an offer, I accepted their offer, and that offer/acceptance was a contract, and I provided them the offer their employee emailed me. He said "No problem" and sent me $125 BEFORE they even received the computer in the mail. I was quite pleased as this was the Puck Pro that they sold to me months earlier and sold me at the regular Puck price, a $30 difference. So they actually paid me $155 for a computer I used 4 months and bought from them for $149.
I've heard "horror stories" about LP, but it has all been from dive shop owners who can't match LP's prices. I've had nothing but a good experience from LP. Sure, they screw up orders just like every other business does, but in my experience they make it right and don't just blow you off.