You would still gain less experience then a solo character per mob. The reason I say this doesn't really matter though, is questing is still your main source of experience, and will still yield the same experience for all your characters. You will tear through quests (some collection quests aside) extremely fast, and with the changes to xp gain and having less xp per level is a big help.

Really, you are losing the xp bonus yes, but it isn't that big of a deal imo.