Not very happy with the Sheppard E LRT plan.
On one hand, LRT (even the TTC design) should work better than just adding "rocket" buses. First of all, "rocket" buses would have to co-exist with local service, and hence the frequency of "rockets" will be lower than that of LRT vehicles. With LRT, all vehicles will be as fast as "rocket" buses, at the same time all being "local". Furthermore, streetcars in ROW will be mostly immune to heightened traffic congestion that we are likely to encounter in the future, while express buses in mixed traffic will be affected. And finally, TTC is too depended on buses to cope well with the future spikes in oil price. Converting major bus routes to light rail will have the effect of diversification across the energy sources.
However, looking at this particular route in the context of the whole system, one can notice two major goals that won't be served well by the proposed LRT: improving overall transit in the under-serviced north-eastern area, and enabling fast E-W crosstown trips in the north. Indeed, the LRT line will help those who live or work near Sheppard E. But people whose origin or destination is at Finch, Steeles, Ellesmere etc., won't bother transferring to that line. Rather, they will take their regular bus and head to Yonge subway or to SRT. In case a continuous Sheppard E - Finch W LRT line is created, it would be somewhat more attractive, but that would incur nontrivial extra costs (in the range of hundreds of millions) on top of what is slated for Sheppard E and Finch W LRT lines.
Therefore, ideally I'd like to see a combined subway / LRT solution for the Finch - Sheppard corridor, that includes both extension of the Sheppard subway, and LRT lines at the edges. Unfortunately, that might be hard to squeeze into the 15-year or 25-year plan, due to other priorities and the funding constraints.
But even so ... 700 or 800 M slated for Sheppard E LRT is a nontrivial amount of cash. That could probably fund the extension of Sheppard subway to Warden, and I wonder if that would be a better investment. Such extension would help not just those who live between Don Mills and Warden, but those who travel along Sheppard from locations further east. Moreover, that length of subway would justify the routing of Finch E and Ellesmere buses to the subway terminus (one branch runs from Yonge to Kennedy, another runs from the eastern terminus to Warden and then to subway). Passengers of those routes would get a slightly faster and much more reliable commute, and fewer buses would be needed during the peak.
Beyond the 25-year plan, Sheppard subway could be extended further (west to Downsview, east to Kennedy and perhaps STC). Once it reaches Kennedy, LRT line could be added further east. We can assume that by that time, the section of Sheppard between McCowan and Neilson will host the STC - Malvern light rail. Then, the marginal cost of adding the Kennedy to McCowan section and the eastern section won't be that high, perhaps 300 - 400 M in today's dollars dependent on how far the line goes.