I'm a HD newbie, so forgive me if this is a dumb question. But, If I shoot a wedding and use the XA20 as a primary cam and XA10 for BRoll...I'm assuming I would need to shoot with the same settings...1080i/60fps or 1080p/30fps (PF30) (no 1080p/60fps on XA10). Also I'm assuming the recording mode has to be the same (ex: 17mbps, 24 mbps, etc)???

Also, I edit with Adobe Premiere CS6 on a mac...I dumped some 1080p footage in premiere and it looked choppy/slow when reviewing...is that a video card issue? 1080i footage didn't seem to have that issue.

Thanks in advance!!!

IMO, to get the very best match of the footage from the two cameras, you would want all of the settings to be identical- including white balance and any custom settings (detail, contrast, saturation, etc.)
The choppy view you are getting on PPro is likely a previewing issue. It indicates that your system is struggling to process the AVCHD frames fast enough to provide full quality playback.
This could relate to the CPU, the amount of RAM onboard, the GPU, or all of the above.
If you set the PPro Monitor screen at 1/2 resolution, and 1 field only (if it's 1080i) the previews will usually smooth out nicely unless the system has a seriously weak link somewhere.

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It usually works best if all camcorders shoot the same settings, and are white balanced to the same standard. However, since they are different models with different sensors and DSPs, there might be differences in some of the custom settings needed to obtain the best image match.

Mixing i and p footage can cause subtle changes in the video you might not want. And different NLEs have different abilities to use mixed format footage in the same project as well. Before a money shoot run some tests to see what works best for you and your gear. You will probably be more critical of the results than your clients (unless they are serious video editors themselves).

Computer screens are usually poor at allowing a critical evaluation of video. And limitations of the NLE software and computer system may prevent smooth motion as well. You really should use a monitor designed for TV signals. A good HDTV works for many people, and cards like the Black Magic Intensity Pro provide an affordable way to drive a proper video signal to the TV.

"Also I'm assuming the recording mode has to be the same (ex: 17mbps, 24 mbps, etc)???"

While it's a very good idea to match the format (1080p30 for instance) between cameras, there is no technical requirement that the data rate match for the editing to work - you can certainly mix the clips in Premiere without issue. However, higher rate = higher quality, so with the cheap price of SD cards, it would only make sense to use the highest possible quality setting all of the time.

How are you importing the footage into Premiere? Improper methods can sometimes result in playback issues. The best way is to copy ALL of the contents of the SD card directly to your editing hard drive. All folders, do not pick and choose video clips, do not use any "transfer utility" supplied by the camera maker. Then in Premiere, import using the Media Browser rather than "File > import". You want to maintain the folder structure and metadata of the AVCHD format for best results.

Also regarding choppy playback, that is the nature of progressive footage versus interlaced, especially with pans. 24p is worse than 30p, but neither will provide the smoothness of 1080i.

Thanks

Thank you all...great information. I will continue to test out.