i dont think that u can judge from a first date, or even two, exactly a persons personality and suitability...
for example, my ex ex boyfriend...when i first met him i liked him...but i didnt see him for two years after that. and when we started hanging out, we hooked up...i wasnt hugely interested in him, and couldnt see things going very far. but he asked me out and i said yes, because i figured id give it a go...and we ended up going out for just under a year...and he is still one of the most important people in my life. i love him to death hes my best friend and we now know and understand each other perfectly
then my last boyfriend...i liked him for quite a few months before we dated, when we first went out i was like omg this guy is perfect for me! i was really crazy and stupid and girly and totally head over heels. but we only dated for a few months, because i all of a sudden realised that we didnt really click.
it takes time to get to know people, properly get to know them. so i dont think that anyone should judge too quickly whether or not someone is right for them or not. its too hard to predict...if things dont work out, then u learn and move on. but if u dont try in the first place, u dont know what u could be missing out on