Have owned our Tuscany for over a year, and love it. Pick any manufacturer, they all have issues, and you will find owners with both good and bad experiences.
As to the two units you're considering, the 42-footer will have a tag axle, and the 39 will not, so that's a substantial difference. Entegra makes good coaches, as does Thor. We considered both last year, and went with the Tuscany, for two main reasons: Entegra only made tag-axle coaches (we didn't want one this time), and we didn't like the Entegras' decor. Apparently the first issue has ceased to be a problem ...
2014 Tuscany 40RX
towing 2016 Grand Cherokee