I believe Evil Geniuses are an OK team. They have potential clearly; their winning streak in Open Qualifier #2 proves it, as they beat teams like the Knights and Girl Kissers (the team that kicked Version1 to the lower bracket). However, when you look more into their history, you see that they've never really been able to beat the "better" teams. Looking at previous encounters, we can see, in terms of total matches won:

0-2 to Cloud9
0-2 to 100 Thieves
0-2 to Version1
0-3 to XSET
2-2 to Knights
(Please do note, some of this data is old and does not account for roster changes.)

If this history ends up continuing, it seems unlikely Evil Geniuses will be able to beat the best teams (except Knights). Therefore, I believe Evil Geniuses is neither overrated or underrated at the moment. With time, we will see how they will perform, and only then will we be able to make a more confident decision as to whether or not Evil Geniuses is an underrated team.