The Downie-Lapierre-Bennett wasn't a unit that was used much. It was just something that got thrown out there a few times over the course of several games. When Bennett was relegated to 4th line duty it was mostly with Adams on the other side.

the Downie-Lappy-Bennett line might be a good 4th line, and it might be something worth trying more. However the chemistry might be more than just positional. It might be a confidence thing. Downie and Lappy may place trust in Adams, that should their push go the wrong way at least Adams will be back there to limit the opposition's scoring chance. They might not have the same confidence in Bennett defensively, which would leave them to not take as many chances offensively. Adams also seems to play better with those two, he plays with a little more jump. I think he feeds off of their energy. Bennett seems to play the same no matter what line he is on. Having a line mate who plays with a little more jump when he is with you can have a positive moral effect on you.

Again, I don't know for sure, I just hate seeing Adams get shit on during the only times he has been effective outside of the PK. Is Bennett the better player? Yes he is, and he should be playing on at least the 3rd line. He needs the experience, which would bump Spaling down to the 4th, and Adams to the press box. I just don't think he is a better fit on the 4th line over Adams.

To me the Bottomw 6 would be:

Winnick-Sutter-Bennett

Spaling-Lapierre-Downie

or if Bennett continues to disappoint:

Winnick-Sutter-Downie/Spaling

Spaling/Downie-Lapierre-Adams

Spaling is little overpaid, but not by much. He is a great utility player. He can be plugged into any line and be effective. He isn't a long term fix on those lines, but it is useful if a player is injured or your lines get jumbled due to special teams.