Just a fantastic article by Ron Goldberg of EH regarding control systems.  If I may add to the cost control, know the true cost of ownership of your control system.  Several types of control systems now employ subscription fees and servicing fees (not to mention programming changes) that will cost you on a recurring basis.  Really try and get an idea when you compare apples to apples what those costs are and what you are paying for.  Also, it’s very easy these days to desire Apple only products for control, thereby saving money and bypassing that touchscreen or controller.  My suggestion is that iOS and smartphone/tablet products don’t always make for the best all-around remote experience.  There are several articles out there that detail why, but as a practice I always try and outfit my customers with a free programmed hand-held with an underlying iPad or iPhone controller that I come and pick up in a week if they don’t want it - free of charge.  I have never received one back yet.  People still appreciate a dedicated device rather than a commonly used phone or iPad for control.  Consider asking your installer to do the same.