If you're talking about the entire run, I would have to vote on 2014 being the more improbable run. People (rightfully) doubted us getting out of the first round and we did that same survive and advance, have fun and stay loose motto as in 2011. There were many factors to both teams and the runs, you have the strength of the star (Kemba vs Shabazz), the strength of the rest of the team, and then the difficulty of the road to take down the title, and the general difference in the strength of the entire college basketball landscape in that year.
So, I think:
Kemba was the better individual player
the 2014 supporting cast was definitely better than the 2011 supporting cast
2011 we got a bit of a lucky path in that we didn't need to go through a gauntlet the way we did in 2014
in addition, the strength of the full field was much greater in 2014, just looking at the quality of players in the drafts after the years can display that.
Theres also the fact that the 2011 Huskies were on the radar after the 5 wins in 5 days, while in 2014 Shabazz's Huskies had a nice run, but couldn't beat Louisville at all.
I think both runs are very very similar in that both years no one would have called us as the champion at the start of the season, during the season, end of season, start of tournament at all, but I give this year's road to the ring the nod as the more improbable of the two