SkyTrain can be completely driver less, the vehicles last longer than LRT, they are easier to build than elevated LRT due to not having to install the overhead wires, they have faster pick up speeds than either automated subway or LRT.
As far as safety, SkyTrain has proven itself to be a very safe system with not so much as a fender bender in it's 26 years. One must also remember that Metrolinx has the LRT contract to finish and I think they would be more than willing to transfer that contract over to equivalent funding to SkyTrain MK11 cars. This is because Bombardier has been really pushing SkyTrain technology and this would further enhance it's NA presence outside of Vancouver.
The SRT is just a spur line while this can be touted as yet another city using it as a main trunk line. The vehicle garage , although, probably will need expanding, is already there as is the operating station. I think Torontonians would be very impressed with the system and the new MK11 cars which are very nice. SkyTrain also has sharper turning radius and incline capabilities than either subway or LRT.
Also extending the Skytrain down Eglin ton would also save a shit load of money. Not only is it cheaper than subway but more importantly it will not require the destruction of a line and then spending a $1 billion to replace it. That's money that Toronto doesn't have and improving the Kennedy station, adding heating mechanisms to the current line, improving the SRT to handle MK11s, and 50 MK11 cars, would cost, at most, $400 million.
At $200,000,000 per km that would pay for 3 km of line. This is to say nothing of the fact that it would be faster to build, have a smaller footprint that at grade LRT, and would not require the SRT to be shut down for 3 years to turn the SRT into subway.
Remember kids, Toronto needs to EXPAND it's mass/rapid transit system and ripping down a line just to build another one doesn't increase the length of the system by one foot. By doing the Pearson/Eglinton/STC line it would mean that the Bloor/Danforth could eventually be extended further east without a transfer as it was originally designed to do.
McQuinty will, and rightfully so, be livid when he has to spend $100,000,000 to cancel an LRT contract. I think if there is one chance that Bombardier waves that cost it will be for SkyTrain to raise it's NA profile. I could see them doing it for SkyTrain but quite frankly not subway.
