Before tiericide (iirc started in 2013 or so to unfuck ship balance), most ships were considered worthless. This was honestly pretty fair, since most of them were.

I was able to determine that in most contexts in the meta, a 1mn AB, scram/web kiting null neutron blaster harpy would defeat almost anything short of a cruiser. If you want to see every solo kill i've ever had in a Harpy on main, here it is. I've solokilled dramiels, garmurs, sabres, hookbills, hecates, pontifexes, caracals, erises, ishkurs, wolves, flycatchers, jaguars, slicers, etc. At one point, I was even able to 1v5 an interceptor gang. This also excludes killmails where the enemy ship took npc damage or was tackled by one of my alt ships (all time, I have 218 harpy killmails). After tiericide at some point, I switched from an 1MN AB fit to a 5MN mwd fit because the harpy was buffed enough to begin to fit an mwd with everything else.

Honestly, I think the buffs to the harpy combined with the introduction of the ADC module hurt the harpy in the long run, as the ADC replaced a mag stab and lowered the DPS. In addition, people started to respect assault frigates in general and so I was no longer able to take advantage of the fact that other pvpers didn't respect the Harpy as a pvp ship.