Welcome Mailman,
Like the consensus, I recommend the Frances for all the reasons above for a 1st Camino. If you continue to Muxia and/or Finisterre then this complete trip exposes you to all the general terrains of the various "other" Caminos. Like a sample platter at a new restaurant, you will be in a better position after the Frances to decide on your favorite preferences for the next one. And who knows, the variety the Frances offers may be your preference again.
I walked mid May to late June last year. The statistics from 2018 prove this to be a busy time of year. A frequent criticism of the Frances is that it is crowded....a very subjective term. Don't let this deter you from the Frances if you detest crowds or yearn for open spaces where you can't hear another pilgrim or even see another pilgrim in front of or behind you. If you desire to walk in a group you can always find one. I never saw a "real crowd" until the last 100 km and even then it was usually a temporary situation, a church or school group or a load of people who just got off a bus and started walking. These crowds tend to be either slower (older tourists from the bus) that you overtake quickly or faster who walk past you quickly (high school kids) than the average walking pace.
Prior to Sarria there were a few times where I could see far ahead on a long winding road, a string of pilgrims, most solo, a few pairs a few foursomes spaced out way in front of me. It was actually a cool sight, because it was unusual and not at all offensive. It actually makes for a good picture. Just like your motor route delivering the mail, there is a predictable and easily avoidable rush hour on the Frances each morning. If you want to avoid the "road rage" (just kidding, there is none of that) start walking after 8am...8:30 is probably best as long as there is not a larger town within 2 hours walking time behind you. If you find yourself unintentionally amongst a group you prefer to be away from for whatever reason, just stop for a few minutes and let them walk by and you will soon be alone again. If seeing 10 -15 pilgrims per day is too much, then the Frances is not for you. Depending on your pace and strategies to avoid pilgrims, you may see 1 or 2 in an hour or 20 - 30 in an hour and seeing doesn't mean interacting, again that's up to you. You really can have it both ways on the Frances.
I attached a few pics of the crowds - see if you can find all 40 of the people in the pic labeled - 40people - you will have to zoom-in on this one and some of the others.