The current Liberal government proposes to change the federal voting system from first past the post (FPP) to some other system that has different flaws to the present one. There is no system that is flawless. There are just different consequences and biases.
A main objection to FPP is that it allows a candidate to be elected with less than 50% of the constituency votes, sometimes in the low thirties depending on how many candidates compete in a riding. Let’s say 65% vote for other than the winning candidate, then the losers object, because the majority winner receives only 35%. The losers want their vote recognized at the polls and to be awarded seats. Seldom mentioned is the possibility of disenchanted voters joining a major party and attempting to influence policy from the inside.
One alternative to FPP is preferential voting (PV) where voters choose their first, second and subsequent choices on the ballot, either on one voting day or more than one. The latter raises the costs of the electoral process and leads to electioneering between ballots. PV can ensure that the winner gets 50% plus of the votes. Its other advantage is that the elected candidate comes from the constituency as with FPP.
PV favours the party straddling the middle of the political spectrum. If in Canada this is the NDP on the left, the Liberals in the centre and the Tories on the right, then the Liberals might try to campaign towards the NDP and Tories to get the needed majority. The NDP and Tories might structure their platforms to appeal to Liberal voters. With more than three parties the politicking gets more involved. One attribute of PV is that the elected person still comes from the constituency.
Neither of these alternatives satisfies those with specialized interests, the Bloc and the Green Party being two Canadian examples. But there are more parties and more would appear with a voting system of proportional representation (PR). With PR, the electorate votes for a party, with seats awarded according to the percentage of votes received. This system favours special interest groups but has other implications. It is often assumed that only existing parties will register for votes, but other interest groups are encouraged to form parties. Persons are elected because they represent certain interests, and not based on representing both a constituency and those interests. Each party decides who will be candidates for election and the link with a riding is lost. (In the 2015 federal election there were as many as ten candidates on the ballot).
For each of these three options there are variations to compare and examples of how voting is performed in different countries can be assessed. According to Wikipedia, there are around 20 different voting systems used for head of state, upper and lower houses of parliament in various countries.
Another information source is in the excellent Danish television program Borgen, where legislating in an environment of many small parties with narrow interests is portrayed. It makes for good viewing if you enjoy watching sausages being made.