Advantages,
If you like driving, its for you. Specialty qualifications such as Tractor Trailer and Bus you could use on retirement. When you are on the road you are basically your own boss, but you must be responsible. TD Trips are great, you make a lot of extra income on those. Snow removal is one of our specialties however on our base is is done by CE and there are only about 5 MSE there, the rest are MDO's. Also, there is basically a positing on almost any base in Canada for MSE Op's. You could also get into AC Refueling or Runway SNIC which would set you up for a job at an airport.
Disadvantages,
Long hours, you could be away from your family ALOT being on the road if you are Tractor or Bus qualified. Being in a Field Support Pl is very repetitive work, from performing monthly inspections on vehicles that haven't moved in 6 months (essentially pushing fresh grease out of the joints with more fresh grease). To having nothing really going on that you're sweeping the floor 3 times a day to look busy. The main thing would be to show initiative and find something productive for yourself to do.
Being young to the trade and the CF, I cannot comment on the longterm. But I have enjoyed my time so far. Just as any trade however, it has its moments where you'd rather fall down a flight of stairs. Also, it is a Army/Air Force trade so you can be either element.