We talked about this extensively. When you group districts together and have a multi-member district, instead of being able to be elected with a small plurality of 30% or 40% of the voters and leaving 70% or 60% or 50% of voters unrepresented, in an STV election in a three member district, only 25% of voters maybe are not going to be represented. There are many more voters the candidates have to campaign for to get votes from.
On the difficulties of getting an MP to help you out, the constituency services part of it right now, if there are more MPs to choose from, finding one should be easier. If there is a choice of MPs, that's fantastic for voters, especially if there are different issues that need to be addressed. If it's an immigration issue, a business issue, or a family services issue, if you have different MPs with different specialties and different concerns, that's much better for voters.