The frequency measurements and spinoramas help you identify a speaker that is accurate. Signal in and signal out with as little variance as possible is the goal. This isn't a sure-fire method of identifying a speaker that you will find pleasing. Research has shown that people tend to prefer speakers that measure well and have good off-axis response. One caveat to remember is that flat lines are boring to the ears. Once you own the speakers, you should season the EQ to taste. Measurements are an indicator of accuracy, the flatter the better. EQ/PEQ/Target curves are for the individual to shape the sound to their liking once its in your home. To answer your question, I bought all of my speakers without hearing them based on their measurements. In my room, I have a target curve that looks like a ski slope. I have not been disappointed thus far. I hope this helps.
Theater Room: JBL M2 (3), JBL 708 (4), JBL 705 (4), Lexicon MC-10, 24" DSS subs (2), Dual 18" DIY subs (2), Sony VPL-HW55ES, 127" Seymour 16:9, Oppo
Living Room: Revel 228be, Onkyo TX-RZ1100, Cambridge CXN (v2), cheapo TCL TV.