I just bought Arrow season 1 and I'm watching the 8th episode now. I really like it, but I like most shows based on comics or people having powers, so I guess I'm a little biased lol. I don't know if it's better than Smallville... yet. Clark Kent was ok in the show but the supporting characters (CHLOE, Green Arrow, Lois, Supergirl, Aquaman, Cyborg, etc.) were great additions to the show. Chloe was my favorite character though. Like I said though, I'm not even halfway though the first season of Arrow, so Idk for sure if Smallville is better. So far I really like Green Arrow, Merlyn, and Helena.
^And Deathstroke was great too.
Idk too much about the DC universe though. I am familiar with Batman and his villains and the major heroes like Wonder Woman, Superman, Green Arrow, Flash, etc.