As Benny stated, if we didn't have Michalek signed long term then I'd be for it. But I'd rather have Smith really than Berglund. He plays his role well. He just needs to shift back to C. He's more effective there.
I don't think this guy is a top 6 player. He's a damn good 3rd liner though.
I don't see room for Smith long term at center though; Turris, Zibanejad, Lazar will all be ahead of him, so best case he's stuck as our 4th line center. We've got Legwand this year and next, Pageau could be playing now if needed.
It's not that I don't like Smith, it's that right now we aren't getting full value out of him, but may be able to get it via trade. Berglund would address an area of weakness (LW), and has upside (I'd rather him filling in for injuries in our top 6 than Michalek or Smith).
I also think if Berglund can be had for Greening and a 2nd tier prospect, we can likely restore his value and move him later in the contract for more.
Edit: I totally understood why people didn't want Berglund as the primary piece coming back in a Spezza trade, but come on, if he's coming back and all we give up is Prince and a cap dump... Sorry Greening, but that's what you are these days, this is honestly a win win situation even if he doesn't pan out as a top 6 option. I honestly can't beleive people are against this trade, imo we are offering too little.