You won't see the tax benefits of incorporating if you're taxable income doesn't reach a certain level.I have enough expenses that I write off (also depreciation, home office, cell phone, etc.) that it's not going to really give me many tax benefits by incorporating.Meeting requirements http://smallbusiness.chron.com/scorporation-meeting-minutes-requirements-62256.htmlHowever, those don't really apply as much if you're incorporating by yourself.  

That leaves management with the task of decreasing expenses, run it more efficiently, but in reality, there is only so much you can do here as a 2-4 unit isn't at an operational level where expenses can be significantly cut.You can't squeeze blood out of a turnip.Chances are, a savvy owner isn't going to be leasing you a property for you to let to someone again at any killer earnings potential, not much more than management fees.

I was wondering if any longtimers have dealt with any significant decrease in market rents or increased vacancy rates?

The Seller will first need to decide if he/she wants to defer all of his/her taxable gain. 

I don't want to sell the land just yet for a huge decrease.

What Aaron posted I took as off topic, as if he was buying partial payments from note holders, if it was meant the way you took it, you'll have an amount as a forgiveness of debt, taxable income.

I find buying the higher end homes are much harder to unload and the amount per square foot decrease the larger more expensive the home!

Tenants are paying this for you and your mortgage is being reduced every monthYou also have write off of depreciation, a non cash expense which lowers your taxable income.These two returns are usually not mentioned when calculating total returns.  

The housing stock will deteriorate in quality and decrease investor opportunities unless we become smart on these new requirements and build them into our costs.- Does anyone have any 'rule of thumb' to estimate the cost of a sprinkler system.

Jon is right moving in will decrease the down to possibly 3%, depending on other factors.