And your INS won't help you land on an IAP - far too inaccurate. You would have to descend over the sea and continue visually below cloud
Of course, no contest. I wasn't suggesting that INS was better than GPS, just that navigation hasn't changed in principle since Pontius was a Pilate.
To assess W/V one started with sticking a wet finger into the air, then we had drift sights ( I was once told that I'd never make a navigator so long as I had a hole in my axxxe, until I'd had to fly a three-wind drift sight calculation over Berlin with the shells coming through the cockpit ) then sextants and an air plot on a chart, then Consol, then Loran, then Doppler, then INS and now GPS - to get the fixes required to apply the trigonometry - and I don't doubt someone will invent an iPod to do it next. The point being that all we are doing is inventing something new to evaluate the data we need to achieve the result. The trick is knowing how to use it - and keep in practice.
I was recently flying my microlight towards controlled airspace, and needed a cross bearing, and instead of pre-programming the panel mounted GPS ( yes, it is a microlight - LSA if you prefer ) I pulled a handheld GPS out of my pocket. I had to see the irony, having navigated 707's with a sextant, I was now navigating a microlight in VMC - with 2 GPS's !! How the World has changed ! But is it for the better ? Do the present pilots understand the principles, or do they just follow flashing LED's !
OK, I'll crawl back into my cave !!