Advice on Swap to Dot 5 - New MC

you will hear all kinds of pros and cons...because water doesn't mix with synthetic brake fluid it will pool in lo spots in your system and corrode those spots.Their should be no measurable amount of water in your brake system unless it's used in all manner of winter and rainy environments for years.Synthetic fluid will give you a soft pedal.Synthetic won't damage paint..for Pete sakes don't get it on your paint!These arguments will go on forever.Your line size shouldn't matter.If you have a hard pedal your master cylinder piston is too large.Different size tires can mess up your proportioning.Due your tests on a damp / wet pavement were there is no traffic.
There are numerous systems out there..i would still duplicate a disc drum factory set up because they got it right and parts are available and cheap. It's like suspension modifications..too many just add on heavy duty aftermarket parts and end disappointed or with poorly performing rides.
Brakes are so important.