As somebody who ends up in a leather suit fairly regularly, let me tell you a few things about suits:
1) Even in cooler weather, they are hot as all F@#$. In warm weather, you’ll be drenched in sweat before you even leave an air conditioned building, and you’ll be ready to die once the sun attacks from the sky and your toasty bike from the below.
2) Suits are very hard to get into and out of because they are made to be extraordinarily tight. Granted, I also have some additional gear that slows me down (chest/back protectors), but it usually takes minutes to get into my suit. It’s gotten better since it broke in, but it’s still a bitch.
3) Once you’re in, it may restrict your motion even once broken in depending on your body type vs. the build of the suit. I, for instance, am tall and relatively thin. To fit my waist size, I end up in a suit where I can’t really stand up. It’s comfortable in riding position (all that matters), but impossible to walk around in. If I anticipate having to move around off the bike (e.g. in between track sessions), I inevitably unzip the suit and pull the shoulders off so I can stand up and cool off.
4) Nothing is less practical for everyday use. It’s hard to carry a wallet, cell phone, documentation, take a piss let alone the other kind, etc.
So why do I have a suit then? Two reasons: dedicated rides and track days. For track days it’s required, and for a long three hour ride at a brisk pace through outskirt roads it just makes sense. You’re on the bike the whole time and the feeling of greater protection (especially lower body) relaxes me, yielding better (and safer) riding.
If you’re worried about synthetics, get a leather jacket. If you can’t take the heat, get out of the kitchen