Over the past few years, the Bruins were significantly better than the Sabres. By far. Not even close. However, this past off season has been a huge turning point for both franchises. The Sabres have made enormous improvement, while the Bruins basically blew everything up.
The Bruins opening night lineup will have no Milan Lucic and Dougie Hamilton. Thats taking one of your better forwards and your best defenseman away from a non-playoff team for draft picks that will not help them right away. They added Matt Beleskey and Zac Rinaldo, but did little else to make a change in their lineup.
At center its pretty close. O'Reilly and Bergeron play similar styles and are close in talent level. Krejci is in his prime and currently an upgrade over Girgensons. However, Eichel beats out Spooner in a landslide, and may be better than Krejci even now. Kelly and Legwand are a wash.
The Sabres win the top two spots as both Kane and Moulson are better players than Beleskey and Marchand. Eriksson beats out Foligno, but Larsson has the potential to have similar production to the aging Eriksson. Deslauiers is a more impactful fourth liner than Talbot is.
Ennis is my breakout star of the year for the Sabres. He's a first line RW in my opinion. Reinhart gives the Sabres another high ceiling player at that position, if he's not at center, and Gionta and McGinn are versatile veterans who can put the puck in the net. Pastrnak, Connolly, and Hayes are all players with good potential, but none have star potential, and all have yet to reach their potential. It's a very young group of wingers. Zac Rinaldo is just an idiot on the ice. Sabers blow the Bruins RW's out of the water.
Ristolainen and Pysyk are good NHL defenseman at the moment, but if they can become great this season the Sabres win this position in a landslide. However, right now they are just "good". The Bruins have proven defenseman in Chara, Seidenberg, and Krug. Chara is not what he once was, and not worth near his $7 plus million cap hit, but he's still decent. Bogosian and Gorges are a very good veteran combo, but both are injury prone. The Bruins win this one slightly, for now.
While Robin Lehner has the potential to be a number one goalie, he has not done it yet and god knows Chad Johnson isn't going to do it. Tuukka Rask is not only a proven starter, but a proven star. Subban is a rookie, but is one of the best goalie prospects in the world. He had the potential to be better than both Sabres goalies. Bruins dominate the crease.
Overall the Sabres have a better team. The teams veterans have similar talent levels, but the Sabres young players have way higher ceilings. Eichel, Reinhart, Ristolainen, and Pysyk have the potential to take an average Sabres team and make them a playoff team. Boston's young guys cannot take the Bruins to another level. David Pastrnak did as good a job as he possibly could last year, and the team still couldn't get over the hump.