The tube is obviously amazing but particularly during the summer months I will generally take an overground rail alternative if one is available. I almost always take a Thameslink to work instead of the Northern line and if I'm traveling east-west (or vice versa) I'll be looking for any chance to take the Elizabeth rather than Central. Far more comfortable.
It was such a needed line if we're honest. If they were smart, they'd close the central line for six months to widen the tunnels in order to accommodate better trains. It would make a huge difference.