Pros
CTT will train you up very quickly, lots of courses, well planned grad scheme and a company I'd recommend to grads and new engineers or those who want/need more training. Most senior staff in technology groups are very good at their jobs and willing to help those who need advice on technical solutions. Large number of young engineers and active social scene as a result.
Cons
But be warned the company falls down on realising how valuable you'll become and thus promoting you, you WILL get better offers elsewhere within a couple of years. There are other issues such as pooled pay schemes and promotions and highly union controlled promotion plan. i.e. you're ranked in regards to others on your pay grade and go up in relation to your performance relative to them not the people you work with day in day out. You can't go up 2 grades at once. Some jobs appear to be ranked as being more valuable than others and it's basically the fire fighting jobs i.e. despite the company preaching that we should all get things right first time, it's the people who either fix other people's problems or their own(!) that get the most credit. Many of the senior managers have their own agendas and in times of financial difficulties your promotions will depend on your personal relationships with them and not your actual performance. Needless to say there are a lot of cliques and if you're not part of them you could find yourself being held back for the most ridiculous things (as you are ranked against others on your pay grade and promotions are agreed upon by all the managers together). All in all, if you can be duplicitous or happy to just have a job you can't be fired from, then CTT is fine for you. If you are looking to really progress in your career quickly then avoid unless you are a grad who wants to be trained up with a view to entering another company at a higher level. If however, you play a fair game and don't hold punches then I'd personally advise looking elsewhere.