Overall, it woudln't be too bad:
1) Dedicated lanes means much less impact from the general traffic congestion.
2) Wide stop spacing - comparable to, or even slightly wider, than the BD subway average (not counting the section of BD east of Vic Park).
3) The central tunneled section will have a positive impact on the average speed. The majority of the riders will use the tunneled section for a portion of their trip.
So, overall the ECLRT could be ranked as about 80% to 90% as "rapid" as the BD subway.
LRT lines running entirely on surface (such as Finch West) is another matter; perhaps they should be ranked as advanced local transit, rather than rapid transit. And that's not necessarily bad, either.