I worked there for about 8 months in 2006. It was my second job (in addition to a 40-hour a week 9-5 job). So together, I was working 60 hours a week between the 2 jobs. It was a lot. For retail, it's a good gig, but it's still retail. I think it depends where your store is located. I was in an area with a lot of rich people and not a lot of actual outdoor activities. So I got a lot of people who wanted to know "where is your North Face?" Many of my customers were used to getting everything they ever wanted, and would get upset over silly things- like having to go downstairs to the customer service counter to pick up an order (we had an elevator), that GPSs were kept in a box, that I couldn't help them RIGHT THEN because I had 10 customers in front of them in line, and all that. It's essentially a high-end toy store. It wouldn't exist without people willing to spend $100 on a pair of pants, but a lot of this depends on your tolerance for serving the types of people who are willing to spend $100 on a pair of pants.
Apart from the customers, the management was decent, but a lot of that is store specific. I had a really great management team most of the time I was there, who would take the heat from problem customers and try to accomodate vacation schedules. And then a couple of months before I left we got almost an entirely new set of managers (kind of on accident, everybody just sort of left at the same time). I got a not very nice supervisor who once corrected my misunderstanding of store policy in front of customers, the end result being that it made it sound like I thought the customer was stealing (I thought it was store policy to bring all ink-tagged items to the counter. She said it was a 'judgment call'. In front of the customer whose item I was trying to bring to the counter. That did not go over well).
The biggest perk is the discounts and pro deals. I dedicated $100 of the $600 I made a month there for gear, and I'm still using most of the gear I got. It's a great way to build a climbing rack, for one. They also tend to pay higher than other retail establishments.
You can see how long you can take it. Some people work there for years, but I couldn't do it.