Sometimes civilian sex IS better. Spontaneous. It can be an all-nighter, instead of just one hour. If she's a real looker, it's a real ego booster.
The cons are, she isn't always a looker (she can be 'nice' looking, just not that 19-year old doll that you spent a grip on a couple weeks ago).
She could be awful at sex (meaning the sex is...ok, but a bit of a letdown). Specific reasons could vary.
Could have an ex, who hasn't broken up with her yet.
Kids....cock-blocking ass kids (as in, you THINK you're going to get some, but that 3-year old just REALLY misses mommy that one night you're over there and won't leave you two alone...at all, for any reason, and isn't sleepy, and doesn't want to go to sleep, at all, and starts to cry and act up, because she...wants...to be with mommy, tonight, no matter what ).
She could change her mind and not be in the mood after all.
That ex-boyfriend can be a cock blocker, too. Picks tonight to want to call her, over and over for silly reasons...and/or may want to 'suddenly' see the kid, that he doesn't take care of (buys her a pair of shoes once a year). He knows you're there, because he's ridden by a couple (or 9) times, and seen your car there.
I've also learned that post hobby sex (meaning sex after you've discovered the wonderful art of hobbying) at times can make you feel like a fish out of water. Sure, we've all had sex before we discovered eccie or aspd or TER, etc, and there was a norm to it. But post-hobby sex has a different norm. It can feel...off, if you're too deep into a hobby sex lifestyle. In the hobby, you're virtually guaranteed to get a BJ. 99.72847145629% chance. Not all civilian girls suck dick. Some. Not all. There can be that awkward 'why aren't you sucking my dick' moment at times, especially if you haven't gotten wood yet.
Some ladies don't like you throwing a used condom on the floor. [awkward pause] I don't know specific etiquette on this, even in the hobby sometimes. There's no exact place to put a switched out condom more times than not, which is why I throw it on the floor before putting on another one. The dresser? The corner of the bed? Where, exactly, if the trash can isn't immediately available or visible?
Or, when you're done with the act (civvie sex, that is), do you cuddle, orrrr...what, exactly? Go to sleep? I've done both, fwiw, but sometimes it can be a bit awkward if there's no measurable intimacy between the two of you.
Depending on these circumstances (and many others not mentioned) civvie sex can be way different than hobby sex, good and bad.
YMMV.