Most all of them are a trade-off, yeah. The best one is the Escort MaxCam 360c, but it's pretty pricey. It's got good performance on the radar side, but needs some firmware updates to button things down. The dashcam is a pretty basic 2K dashcam. I use mine as a rental car setup to quickly toss into the car on a trip, especially when I'm not as concerned about parking mode.
There were some other combo units from companies like Cobra, Whistler, and very very briefly a company called American Radar, but none of those were really all that great.
Another option if you really want something somewhat integrated is to get an Escort M2 which attaches to the side of your existing RD and shares the same mount and power cable. It can also be used with some Uniden radar detectors too. It's again a not particularly good dashcam and it's only 1080p, but if you want something kinda integrated, that's another option.
Personally I like to keep them separate to get a really good RD and a really good dashcam because you wind up with something that's better on both sides. Sure you have two devices, two mounts, and two power cables, but it's definitely worth it IMO.