MTS and MP4 are just "containers" each with their own strengths and weaknesses, but since you are looking at making either DVDs or BDs then the choice of container is largely irrelevant. I'd suggest that you make a short 10 sec sample using each and check:
- what the Video Stream Specs are (eg 1920x1080 @50i AVC etc)
- what the Audio Stream Specs are (eg DD 2.0 etc)
- that you can load the samples into PD11
As Dafydd said, you absolutely want to pick a recording format that is similar to what you plan to create in your project. Picking the same Frame Rate is most important, eg if you are in a NTSC country then rates like 60i or 60p will work better than PAL 50i or 50p. PD11 will do a fine job in changing the resolution so you might as well shoot in HD even if only making DVDs…. but nothing can smooth out a video with mismatched frame rates.
If in doubt, post more details of the Camera (so we can see the specs) and/or the two samples and some more details of if you are in an NTSC or PAL country etc.
PD 64 Bit-Win10 64 Bit-32GB RAM-80TB HDD
Sony FX6 - 500Mbps 4k/50p AVC-I HLG
Canon XF400 - 150Mbps 4k/50p AVC
GoPro Hero6 Black
Pana HS700-28Mbps 1080/50p AVC (High@L4.2)
Canon HV20-HDV 25Mbps 16:9 1440x1080/25p MPEG