The Astero is a nice looking strong ship.
It may lack some of the warp speed, nullification and scan bonuses of the T2 exploration frigates but makes up for that with superior combat capabilities.
Personally I mostly fly T2 explorers (Helios) for exploration instead, but would consider the Astero if I also wanted the capability to ambush other explorers while I explore.
My recommendation is to only fly the Astero if you make use of both the covert ops cloak and of it’s combat capabilities with drones and tackle to kill other explorers.
If that’s your goal then the the Astero is a fine ship.
If you’re not looking to fight and/or cannot use the covert cloak yet it’s a waste of an expensive hull to fly the Astero instead of a cheaper option like a Heron.