John nailed the answer and took the words out of my mouth. It is increasingly difficult to get financing as increasing bank owned units add to the non owner/rental ratios and lawsuits increase. Homeowners with the "Lets get them/sue" mentality have ruined it for the other condo owners who don't want to sue.
Condos and other HOAs in general are a breeding ground for construction defect/reserve deficiency attorney's with their barage of letters and Homeowners and HOAs get lured into them as they use the old "we found one with problems, can we come look at yours for free" line.
Unless there is something special; on the water, ski slopes etc; they tend to go up the least in an up market and down the most in a down market, 2nd only to time shares in the bad real estate investment world.
On the other hand, they are great for someone who is unable to maintain landscaping, travels a lot etc.
There are many factors to consider before purchase of any type of property for investment be it a condo or a single family home. Does the investment property pencil, i.e. generate enough cash flow from rental to take care of payments, HOA, and maintenance? Condo's can be harder to sell as lenders are less willing to lend on a condo if a majority of units are rental units. HOA reserves and possible association litigation against the builder can also be issues.
A good agent can do a lot of up front work for you to determine it the condo has any warts and advise you regarding your potential purchase.
Please let me know if you have any questions.