I recently had my xbox 360 upgraded by a small family run company Karen and Marcus called
xbox-360-repair-servicesKaren and Marcus have been established since April 2004 so they have been going on for at least 4 years and they only specialize in xbox 360 repair, modding.
Anyway i handed in my xbox 360 at 1230pm afternoon for firmware upgrade and new fans put in the console for £50 i collected it locally and it was done at 1700pm the same day which means it took them less than 5 hours which is great for me.
They do nice illuminated cases, repair 3 red lights and laser replacements and you can ask any questions about xbox 360 problems.
They were very quick, efficient and i would recommended there services to anyone.