Camino del Norte v. Via de la Plata in May?

I've wanted to walk the Camino for years. My husband and I are/were excited about the prospect of walking the Camino del Norte in Spring 2018 but now I'm second guessing whether we should walk the Via de la Plata instead. We have some flexibility on dates in May/June but our preference would be to start in early May and finish in early June (4-6 weeks). We initially chose del Norte because I don't want the crowds of Frances and Galicia is the part of Spain that I've never visited, but I'm nervous about the pavement (there seem to be lots of complaints about it) and the weather in May. I know I'm posting on the del Norte board so there may be bias, but what are people's thoughts on Camino del Norte v. Via de la Plata in May?

A few things about us: We're in our early 30's and in shape. We'll prep some for the camino but we're not going to be doing a hardcore training regime. I'm not so much of a purist that we have to start at the beginning of a route. (I know VdlP is longer so we'd probably start at Merida or something.) I would be fine walking the camino in solitude but my husband would go crazy so we don't want to be at either extreme. We are very unlikely to have this kind of time off ever again (we're on sabbatical) so, realistically, we won't have the opportunity to do one of these routes at a later date. Thanks for your advice!