Unfortunately it is unlikely to actually improve trip times in to the city. So don't know if it will improve suburb values but rather detract from those which the road effects, i.e the inner north as listed previously.
It is like widening the Monash, it is all a bit of a furphy of chasing our tail trying to build more of these roads and widen them (like they want to do with the tulla). You still have the same amount of traffic, this represent a physical footprint size, by widening you just squish that footprint in at the ends doing hardly nothing. Also at the end of freeways (i.e the city where the majority of people are trying to go) you always have bottlenecks, there is still going to be significant traffic along Hoddle/Punt. Remember also on all of these major road building projects that have happened around the country (Brisbane tunnel, Sydney tunnel, Melbourne East Link) none of the traffic figures used in the business cases (often not revealed till after it's built) have even come close with the projects not making money for their owners/operators. It's a disgrace how these major projects are getting pushed through government without the release of the business cases.
No city in the world has reduced congestion by building more roads. We need better planning policy and ideas to get people off the roads we have. I.e public transport needs to be faster/cheaper than a car trip for the same journey. Cities which have successful systems this is one of the biggest drivers, time saved. Unfortunately in Melbourne PT often isn't faster.