As hated said, most class have more damage with basic gear then summoner with good gear.
I made a gunner with no bad weapon, basic gems, no amulet, no coumpound, no insigna, no unity and my damage was 45/50m
Then my main summoner with shadow fury stage 3 +6, better gems, poharan shield, full skystealer +6, decent compound, decent insigna, decent unity and my damage can go from 20m to few dungeon to to max 40m with a miracle. What's the sense in using lot and lot of golds to just reach the level of other class but with just the story ended?
How can this even be good in longer fight? There is no need to think what is better, if 150m or 40m. Simple it's not that good for longer fight. And what about solo dungeon? I dubt that a longer fight make it easier.
And Neeoki, about the grab, u should play a spec more weak then the 3rd. The damage will go down to 15m/20m so no worth.
Summoner really need a huge buff, atm is really bad im not surprised only few people play it