The print quality from places like Boots, Tescos or Snappy Snaps just don't compare when it comes to sharpness, contrast and saturation to my printer. But you need to make sure you machine is calibrated.
I use the printer for doing larger prints, when it comes to bulk prints like holiday snaps then i stick them into the high street places. But if its for the wall, college or work then I use my printer.
Plus the fuckwits in those shops keep cropping my images when they are set-up for the correct print size whether i use a bleed margin or not.