I'd make sure that they did more than that. Detection as a focus has two issues:
- it makes some things hard for the GM, as far as keeping things interesting and exciting. If things are going overly easy they can't just be 'a janitor happened to be grabbing a nap in that storage closet you are going by and looks out at the noise of your passing, and screams an alarm' because you are like 'Did he really resist my 7 successes detect life spell with a 42 meter radius?' Some detection is smart playing, but the always on know-what-is-happening does kill tension.
- detection is passive. It helps avoid surprises and maybe find the route of least resistance, but it doesn't help you get through a locked door or deal with guards who can't be avoided or convince the receptionist that you really are here to see about the roach problem in the executive suite, or take out that huge fire spirit that is eating the Sammie's face, or whatever.
Fortunately, magic is super flexible, and powerful. If you have a mentor that helps detection spells and have a specialization in detection spells (along with magic 6 spellcasting 6), you are tossing 16 dice, which will overcome most resistance pools handily. Perhaps add in a good detection sustaining focus (force 5?) so that at least one spell can be kept up without handicapping you. Then have ~5 detection spells (say detect life, detect enemies, clairvoyance, [sense=ultrasound] crytesthesia, analyze device), that would still leave you five spells to have a bit of combat and illusion or manipulation, which even at pools of 12 dice is still pretty useful.
And just a thought about regular mage versus mystic adept. Regular mages get astral projection, which is arguably one of the most potent information gathering abilities in the game.