Wow, amazing work. From the fonts to the lines to the scale, this map is incredible to look at! There are a lot of specific details and decisions you made I want to comment on, but it's pretty overwhelming and hard to nitpick given the size and quality of this thing.
Thank you!
For the major things, it looks like you had some fun with the subway lines, particularly the Sheppard–Spadina–Relief-Line Loop! I also like how you divided heavy rail services into local, express and "Regio", that makes a lot of sense to me.
When you look at the service plan for the Spadina Subway, there are trains that short-turn prior to reaching Vaughan Centre. Rather than short-turning, I think it makes more sense to have them branch off. The core segment of the 4/5 route (Wilson to Don Mills) needs more frequency than the branches do, so I figured 2/3 (peak/base) on the core and 3/6 on the branches would be sufficient.
For heavy rail, yes I think that division makes a lot of sense as well. Not only is it for mapping purposes, but also for the customer expectations in terms of frequencies and span. Metro would be near-subway level service, while Regio would be a lot more like current GO Train service. I also specifically chose those names because, as a Provincial service, the names should be bilingual.
I hate to bring this last bit up but the legend for X10 has the subtext mixed up. I was also going to mention that "Heritage Greene" in Hamilton is spelt without the last "e"; while that's true for the name of the area, the official name for the shopping centre does have that extra "e".
Thank you for finding that! I copied the text and pasted it down the line, and I guess I missed changing that one. As for Heritage Greene, I went by what was on the sign out front. Also, the HSR will be using "Heritage Greene" post-Re-Envision. Metrolinx naming guidelines also suggest using the name of the neighbourhood, and not a specific corporate name.
Slowly digesting this and am amazed at the number of connections at Dundas West/Sherbourne stations. As many as there are at Union. Now I know that's as much a function of the design style chosen for indicating different service types, but still...
Anyone who looks at this and doesn't see the potential for Dundas West/ Sherbourne to become a true second downtown is blind.
I'm assuming you meant Dundas West/Bloor? Yes, that will definitely become a major transit hub, with the potential for significant densification as a result. Hamilton Gateway (Dundurn & King) has a similar grouping, with similar potential.