Why not a little of both? You can be personal with someone and professional. It doesn't have to be just one or the other. Considering selling art is business, yes, you have to try to keep a good standing with your client so that they spread your hype through word of mouth, and even come back. Part of doing that is doing work for them that is memorable, to their liking, and timely. It may not be dead on time, but being incredibly late with the work (more so after they've paid you), will make them less likely to come back to you with ideas, regardless of your price being fair or no (that part, I'm saying through being a customer that had to wait a YEAR for a commission I paid for up front, per their request
Loved the art, it was breathtaking... but it was too long of a wait for it, and too many excuses as to why I had to wait).
As far as "feeling special", having an artist interpret my idea IS special. Do I need to feel like the artist's center of attention because they're working on a piece for me? Nope. But at the same time, being that the piece is going to be somewhat personal regardless, I'd like that they take some notes on the subject they're drawing (color palettes, references if given, etc.), and that should give the piece merit enough