My biggest problem with using a laptop for navigation is that its a laptop! A spilled cup of coffee can render it useless, not to mention a good dose of saltwater. For backup, sure, why not. But for primary nothing beats a dedicated chartplotter. Even better if it does radar too. I can dump bucket after bucket of seawater on my Furuno and it keeps working. And likely, thats what will be happening when you need it most. If I was choosing a new CP I would go with a Furuno Navnet 3D. Not cheap, but digital radar and all the charts are INCLUDED! Charts are free, vector or raster will work, or you can purchase Jep or Nav if you want them. My understanding is that you can load any chart format and it will work.
Understand that I boat in a sometimes congested area, tight quarters with commercial traffic in pea soup, can't-see-the-bow, New England fog. Messing about with a laptop in that stuff? No thanks. RT