It was many years ago, but I do remember drinking keg Red barrel and being disappointed that it was nothing like the pint I'd had before, at the time I was convinced I'd had cask red barrel, however a quick google search http://www.retrowow.co.uk/retro_britain/keg_bitter/watneys_red_barrel.html shows you are correct and it was only keg, Watneys did brew a Watneys special bitter at the same time which was a traditional cask ale. I guess my relative inexperience at the time, and the pasage of the years had convinced me they were the same drink. So its official Red Barrel was as ghastly as it's reputation suggests with no redemptive qualities at all!
Red Barrel was disgusting and keg beers like it actually encouraged the ordinary pub drinker to try that European stuff called lager. I remember LaMot being served at The Cowherds, back in the late 70s [10CC's - I'm Not In Love was always on the jukebox] and for a while it became my pint of choice. It was cold and sharp to the taste. Then one day I remember popping into the Park Inn, in Shirley, and finding they had something called Wadworths Old Timer newly in on draught, as it was a winter ale and it was the end of October. Drinking that first pint, I went from uneducated twerp to being on the road to recognising the Real Thing, which is what cask conditioned beer is. Little did I know, at the time, but I'd just drunk one of the all-time greatest real ales. Try it, if you can find it. Old Timer is now rare at the pump, and is only a suggestion of its true pump beer self, when served in bottles.
Can anyone remember the name of the Marston's pub that was situated at the back of the old Hants & Dorset bus station (now demolished) opposite the Civic Centre where Matalan now stands. We always seemed to end up there just before closing time, before going on to the Top Rank, and they used to serve Owd Rodger which was the strongest beer we could find anywhere at 7.6%, it was so thick and dark you could almost stand a spoon in it and tasted so bitter. We used to have a competition, whoever could "down it in one" the fastest (without throwing it up!) won the kitty. I quite often had a cheap night after that!
You're thinking of The Lord Louis, and I do remember the Owd Roger that was served on the bar. It was flat and frankly, slightly disgusting, but it started the evening off with a bang. I preferred Barley Wine if the intention was to go down that route, but that's another story. One night, I remember meeting my old drinking pal from work there, and he'd had a couple of Owd Roger's before I turned up. I had a couple too, and he joined me. So that made at least four for him. I have this vivid memory of his disappearing off to the toilet and when he came back there was something like porridge on his shoe. I enquired, and he sheepishly told me to visit the cubicle in which he'd been. I opened the door and there was projectile vomit from floor to ceiling, with not one speck of it in the bowl..! We left the pub as soon as I came back out of the toilet.