Better, not neccesarily much better.
Terry and Koscielny for a start are better. Cahill had been playing in the level that Smalling played last year, for more than three years. Kompany before last year was better too (although last year he was quite shit, so worse than Smalling). Demichelis was as good as Smalling last year. I would say that Skrtel and Mertesacker were playing on his level too.
Regardless that people here are saying that it isn't based on the last two matches, it really is. I don't remember this thread being made last year, when Smalling was generally pointed to be the best of a bad bunch. He wasn't even a sure starter (although that to a degree is because of LVG), but when Jones is ahead of you in the pecking order, something is wrong. When the goalkeeper is the best player of the team for two years despite that the team concedes a lot of goals, again something is bad with that defense.
Anyway, would be interesting to see how many non-United fans would agree that Smalling is the best CB in the league. My prediction would be that the number would be roughly 0. We have a reputation of overrating our players (Rafael, Jones, Evans, Cleverley, Nani, Fletcher, Welbeck, Kagawa) in the past, we are doing it here.
For Smalling to be the best CB in the league, I would say that he has to play as the best CB in the league for at-least one season, probably more. At the moment he is a very good CB, in top 5 in the league (would be tempted to say that he may be even in top 3 - between him and Cahill), but not the best. When he becomes the best - contrarily to people beliefs here - he would be accepted as the best outside of this forum/United fans. For example, De Gea is regarded as the best keeper in the league even by most of Liverpool fans.