I lean towards Stipe, however it's hard to pick a certain favourite with the smaller cage.
It's interesting reading most of the comments on this page, a good percentage, seem to remember the 2nd fight as one which DC was completely dominating... This really isn't the case, round 1 was a clear win for DC, but he wasn't exactly "dominating" Stipe, he wasn't battering him on the ground or anything along that line, standard takedown and winning a round. Round 2 was in favour of DC, however he did also just casually stick his finger in Stipe's eye. Both did damage, DC did a little more. At this stage it's 2-0 DC, however he seems a little bit more fatigued then Stipe. Stipe edges the 3rd similarly to how DC won the 2nd. Nothing too major, no one gets rocked, but DC is clearly more fatigued, the evidence is in his body language. Round 4, Stipe is clearly starting to take over, his movement is better, he's adjusted with the body shots and eventually gets the finish.
If it wasn't for the smaller cage, it would be hard to see how anyone could make a great, logical argument that Stipe shouldn't be the favourite, younger, more durable and found a specific exploit he could use against DC