Cheers Tijs - this is an excellent addition for SummitPost. Thanks a lot. I will be going over this with a fine tooth comb over the long months ahead between now and February 2018. If all works out I hope to be able to add a few photos - and perhaps a route page. I have heard your warnings about penitentes and river crossings along the normal and Yeso Valley routes. At the moment I am attracted to a traverse from San Jose, which I'd also like to climb - and my initial research suggests could be managed without need for a rope, has less penitentes and less serious river crossings. Having said that it would be a committing route with one or two nights at a remote camp on the other side of a 5500m portezuelo...
We'll have to see - at the moment there are other challenges to face like the cost, time off work - and the advancing ravages of advanced age (I'll be 57 in 2018 and painfully aware that my performance is not going up)