Best option for paid upgrades to UK/Europe?
Hello, I am based in the USA. I have depleted my miles and points but my mother in the UK has fallen ill so I may have to make a few trips over to the UK in the coming months. I'm planning to book economy flights and then try to upgrade. I have a few points (like ~50K for each program) but not enough for full lie-flat tickets. What are the best options? I have used AA C-class before (25K + 350 USD) and I have paid at check-in to upgrade to CW on BA (usually ~1000USD). But I've never tried UA,DL,LH,AF, AC etc. Any advice? I suppose I'm looking to understand best value (AA>BA IMO) but also best chance of being successful. Thank you in advance for your advice!