@Chris Purcell
I'm somebody that likes to keep situations simple, and by letting emotions and how you feel get involved, one can make any situation very complicated. If the market is indicating to raise the rent, I would. If they are a good tenant, and you are a good landlord, then they may understand. It's definitely always nice to show some kind of rental trend in the area to the landlord via a graph or what not so that they understand.
I just purchased 2 4 plex, and sent out a 60 day notice to increase rents. The previous landlord didn't take care of the tenants or fix simple things that the tenants needed somtimes for months. The day I purchased the property I let everybody know via notice that I would be fixing any problems that they may have such as plumbing, electric, whatever. I have given them a good impression, and every single tenant has signed a new lease. 6 tenants had their rent raised $100, and 2 had it raised $150. They're happy and understand that they haven't had a rent raise in 3 years, they are still slightly under market, and rent raised 20-30% in the past 2-3 years.