Hi
I used this company.
US$15.
I needed to Order GCMS notes to get an idea of what was happening with my application regarding criminality and what they were "saying" within IRCC and if they had done anything or planning to do anything about it. It's a long story about what's going on there but for your questions...
I requested them on 15 March 2018 and received them on the 18 April 2018. so about 35 days or so. This included some public holidays (Easter. Good Friday etc) so not to bad.
There is a sticky post on the forum somewhere here that goes into detail about reading the notes and understanding what IRCC are saying (once you receive your GCMS notes of course) search GCMS and it should come up.
I believe it's secure and haven't had any issues since requesting them.
I'm not using a Representative/lawyer so I'm not sure if they have to request on your behalf.
The form does need to be signed by both the applicant and sponsor as it relates to their information release as well.
Hope this helps