I'm slightly less optimistic about Denver's growth in the future. I think the housing development projects, especially multi-family, are starting to catch up with the influx of people. I have no concrete numbers, but i did count 12 tower cranes on the downtown skyline last weekend. This coupled with an expectation that the population growth will slow in the coming months will create an abundance of multi-family and consequently a price dip. Again I'm going off anecdotal evidence here, but I believe a large number of transplants are here for legalized marijuana, and with state regulations tightening as well as more states legalizing, along with all the other factors at play (such as skyrocketing rents), we will see a steady slowdown of population growth. I don't expect a crash or even a recession, just the end of a boom, possibly starting as early as next year.
All that said however, I agree with the notion that for long term buy and hold investing, market cycles are less important. If you can get deals near the bottom of the market that's great, but not necessary. Far more important to you are the kinds of numbers provided by Travis Sperr, that an average annual growth of 6% over 60 years means all you need to do is cover your loan, and if things DO go bad, all you have to do is wait. In 30+ years when you decide to retire, there is practically no chance you will have lost money.
For me personally, I plan to get started as early as possible and just deal with a hot market. Then when things do slow down i'll have my feet wet and I'll be positioned to capitalize on the increasing supply of good deals.