I'm just one week earlier than you in the time line!
Basically, you get a less detailed response from the webform, but the response is quite fast (usually 3-5 business days). They will tell you something like "your eligibility is valid, your criminal background is under review, and your security check hasn't been initiated. Your visa office is Ottawa," but that's about it. Sometimes it's even more generic. IRCC's instruction says that they won't get back to you if your application is still within the normal time frame (6 months), but in reality they do it anyway. Be sure to ask them specifically about your eligibility status, criminality status, security status, and visa office if you want. To submit webform inquiry, go to
https://secure.cic.gc.ca/enquiries-renseignements/canada-case-cas-eng.aspx
On the other hand, GCMS notes are much more comprehensive, even redundant. They are usually around 100 pages long, depending on where you are in the process and how complex your application is. The document includes every single update to your file, every note IRCC officers added. Most of the document doesn't provide any useful information though - usually you are only interested in a few pages. To order your GCMS notes, you need to go through a Canadian company/agency if you are not physically in Canada. Doing so costs ~15 dollars depending on the provider. IRCC is "required" by law to send you the notes within 30 days, but they can request an extension due to their workload (and they often do). It's reasonable to suppose you will get them in ~40 days. getgcms.com and gcmsbuddy.com seem to be popular places to order the notes.