I hate the 17th amendment. I understand there were problems such as deadlock and corruption that gave incentive for a change, but as is often the case, instead of trying to fix the problems, we decided we would just get rid of the process altogether. However realistically, I know that since people almost never consent to giving something up, no matter how negative is it to not do so.
The point of having the voters elect the House and the legislatures elect Senators was a good one. In the House, everyone has roughly the same number of constituents, and since they are relatively few, have a much better track record of responding to concerns, wants and needs of those constituents.
On the other hand, Senators have wildly different numbers of people to represent and generally are very bad at handling constituent demand.
Another big issue is that the state themselves lack any representation in Congress, which explains much of the federal usurpation of states rights as time has gone on. We still got to pick our Senators, we just did it through our state legislatures. This was another big reason why this was originally the law. We are not in fact a collection of small political subdivisions, we are a group of sovereign nations that have banded together in one and shed some sovereignty to the collective, but not all of it.
I have a compromise that I think is pretty clever, given that it improves on both the old and new models. Instead of directly electing 100 Senators, we could elect 50 of them. Each state still gets 2, but the state legislature would elect the other. In that way we could return to having state representation and still keep direct election. No one has ever said it has to be one way or the other. Another idea is that either the people or the legislature could vote on a number of candidates and send a pre-vetted group of them to the other party, (leg. or the people) for choosing.