I don't think you need to do you training in A big center to get to the airlines. The school I trained at (Bar XH) has former students at every major carrier in Canada. One of my mates on my CPL is at Cathay. It's more about your collective experience and attitude that gets you the job. Most companies now use a "hire attitude, train for skill" policy. This has more to do with having good employee morale than anything. That said time in the log is still a big factor.
As for dismissing a small center. I think most people would just assume that small centers don't have the facilities that larger ones have. This is not necessarily true.
Medicine Hat where I did my training has 4 approaches. 1 VOR, 1 NDB, and 2 RNAV approaches.
Within 20 minutes at lethbridge they have 5 approaches. 1 ILS, 1 LOCBC, 1 VOR 1NDB and an 1 RNAV.
Then within 50 minutes at Calgary (4 Busiest in Canada as of 2002 probably higher now) There are 3 ILS and a VOR approach.
There are also two other uncontrolled airports with approaches within 1 hour of Medicine Hat.
Yes you have to fly some cross country to get to the other airports but what is wrong with learning how to use the system and plan IFR cross countries. I know that schools with all the necessary approaches on the field still have to do the required XC work but you normally only get the minimum. Also those schools tend to train exactly the skills test you will take. I know this because when I instructed at a busy field all we were allowed to do by ATC was the skills test profile.
What I really want to get across is do your research. Had I not done my due diligence I would not have trained at Medicine Hat. You need to research the school. Find out what equipment they have and find out what the experience level of their instructors is. When I went to Bar XH all the instructors flew in the Medevac and Charter operations as well as instructed. So when my instructor showed or explained some thing about IFR I believed him since they had the experience of being out in the soup the day before.
The funny thing about Canada is that a smaller cities tend to hide enormous resources. Who would believe that a city like Medicine Hat (64k) is Home office to a 20 aircraft operator with a training school as well.
Yes I did train at BXH, and training at BXH has not hurt my career. Colonial