I regularly use the LNER (London North Eastern Railway) train service from London to Lincolnshire but usually travel by standard class. But in a bid to see what I was missing 'on the other side', I recently upgraded to First Class. The experience was much pleasanter all round and now when booking, I will investigate premium options. With the new Seatfrog app it's now possible to bid to upgrade your Standard Advance ticket from as little as £5. To start, a first class ticket with LNER gets you access to the lounge at Kings Cross station in London. The space is modern and clean with comp...