This early into the season, it can be tempting to look at the conference standings and think that points percentage tells the whole story. If that's the case, Ottawa has five teams to leapfrog to sit in the final wildcard spot.
I tend to think goal differential tells a more compelling story, and is more of a lead indicator of regular season success. Over the last two seasons, all top 8 teams in both conferences in goal differential made the playoffs in three of four instances. The Capitals and Islanders last year were the anomalies with negative goal differentials while qualifying. So it's usually a pretty clean way of analyzing how the standings will sort out in the long run.
With Boston in third place in the division, holding onto a -18 goal differential, history would suggest that they are highly likely to fall down the standings if they continue to play at that level game in and game out.
Ottawa's goal differential is -1. That has them at 9th in the conference. All this to say, it's a long season, and their play has them in the race.
Are they good? Their starting goaltender has been bad. History would suggest he individually is due for an uptick in performance, although the Senators' defensive play has a tendency to make most good goalies play poorly. So who knows. Meanwhile, their power play is excellent - fourth in the league. In sum, I don't know if they're good, but with their goal differential hovering around even, they aren't bad.