The subtle nuances between apartments can either be a source of frustration, or an opportunity to sharpen one's apartment-shopping (or in this market, apartment-hunting) skills. Though it's difficult to talk abstractly about what makes two apartments different, it is possible to consider what to look for (or not look for) when comparing two apartments.
Unfortunately, unless your price range is one that would allow you to fund the construction of an entire condominium building, there's usually a compromise of sorts that must be made as you look for the perfect apartment.
One will have the perfect kitchen, but will have a tiny bedroom. The other will have a grand, bright, and inviting bedroom, but the kitchen will consist of a mini-fridge and hot plate that have been helplessly abandoned and haphazardly set up in a cozy corner just off of the bathroom. Entertaining? I hope you don't mind your guests using the end of your bed as a couch.
Perhaps the key in making the shift from frustration to opportunity rests within one's ability to imagine. As you're in Apartment A imagine yourself in Apartment B, and vice-versa. Is the you in Apartment A jealous of the you that's in Apartment B? Is the you that's entertaining guests without a proper kitchen but sleeping luxuriously in a bedroom with skyline views happier than the you that's entertaining guests in a lavish kitchen, but then going to bed in a bedroom that's slightly larger than a closet?
More than likely, these answers won't be readily-apparent. However, if you take your time and continue asking yourself (as well as those close to you) the right questions, eventually, you'll get the right answer. And from there, you'll know, exactly, why This Apartment isn't That Apartment.