First I like to point out, people are saying Supergirl is really hot. No, no don't take my word for it. Jeb Bush said so.

Jokes aside it seems an ok episode. The villain seems to share a similar name to Superman villain Vartox, but is more like the Legion of Superhero villain Persuader. I sure hope they don't go down the route of "villain of the week," with each villain dying after an episode because that would suck.
There are a few things which bug me, ie how quickly Henshaw decided to let Supergirl stop the villains instead of insisting his department handles it. On reflection though, it would have most probably bored me if we have to spend time for Supergirl to convince Henshaw to let her help.
Overall, seems an ok first episode and is enough for me to watch a few more.