1) Powerwashing is more difficult to do, longer to complete, and messier than I anticipated. What I thought would be a couple hour job turned into an eight hour marathon. By the end, I was drenched, cold, tired, and hungry. Sawdust covered the entire deck and part of the house. It's no surprise I didn't have the courage to come back to this for nearly three months.
2) Wood weathers really quickly. It seemed like hours. But certainly after a week or two. Much less a couple of months. Since it had taken me so much time to get back to this project after power-washing it, I now needed to clean the wood to remove the weathering that had formed.
3) Wood cleaners are different even if they're called the same thing. I used two brands of brighteners and cleaners. And they were different. One caused a slight bleaching action. The other just removed the weathering. Lesson learned: Use the same product throughout. My excuse: I didn't buy enough the first time and ran out to the nearest store - not the same store - when I needed more.
4) Rollers are fast to apply stain/sealer but lead to a less uniform coat. This was truly faster than brushing the entire deck. But you get some lap marks and areas that aren't as dark. I even did a second coat (We'll see how that holds up over the winter. The directions didn't preclude doing it, but the rep at the store didn't recommend it). Frankly, after all of the time required and taking two additional weekends after the power-washing torture to clean and seal the deck, there was no way I was going to use a brush. Perfectionism would have to wait for a different project.
So is the deck perfect? No. Is it much better looking? Oh, yes. Is the wood protected? Absolutely. And that is the most important question.
Will I hire this out next time? If the bank account allows, you betcha!