There are a lot of people who like the later seasons. I'm not one of them.It's interesting that you don't like the later seasons. Most people would say they are better than the first three.
As for me, I find Voyager to be of excellent quality from CARETAKER to ENDGAME.
Did you ever see Season 7? That's one of my fav seasons. Tom and B'Elanna simply shine in that season!
See, in my country, you can't even buy VOYAGER. It simply has never been released on DVD here. Thankfully, people have recorded the episodes from various TV channels so this is how we have access to them.
Anyway, what's weird about BEFORE AND AFTER?
I never watched season 7. My Voyager watching is a somewhat odd story. I actually stopped watching Voyager after "The Gift" and didn't watch it for almost two years.
Then I changed my mind and started to borrow VHS tapes from seasons 4 and 5 to catch up with what I've missed so I was back in the scedule in season 6.
Then came a certain disgusting episode which made me totally lose interest so I stopped watching. The only season 7 episode I've watched was "Endgame". I suddenly wanted to see what would happen to my old heroes when they got home so one minute before "Endgame" started on TV I made my mind up and watched it. Unfortunately, I must admit that I was very dissapointed with the episode.
As for Voyager DVD's, can't you buy them from Amazon?
As for "Before And After", the whole story is a bit weird with Kes living her life backwards, Janeway and Torres are dead, Kim together with Paris's and Kes's daughter and all of that. Still on my top 20 list!

As for Voyager seasons, the best season is season 2.

All episodes are great, maybe except for "Threshold" and that episode is actually a bit funny and watchable if you imagine that the events in the episode is a nightmare Paris had after eating too much of Neelix's food.
I consider Voyager's season 2 to be the best in all Trek series.