Well let's see.
He made Cricinfo's 2nd XI, Martin Crowe called him the best post war opener, and he makes his second XI as well, Mark Nicholas also has him as his opener in his all time XI, the roar did an XI to face the Wisden's XI and he was the opener for that, David Gower rates him top 15 all time as a cricketer, Lillee has him as an equal to Viv Richards and Garry Sobers as the best batsmen he's bowled to, Pollock also has him rated equally as a bat to Garry Sobers, Bradman called him the best opening batsman he ever saw, he saw Gavaskar and Hutton.
All this before I have mentioned that between 1970 and '76 he was the best batsman in the world, in '78 when WSC needed an opener he was the one chosen, in a contemporary world XI in '75, Barry was the first name on the team sheet, do you know who else was opening in 1975?
You might say he didn't have a full test career, you might even admit that you don't know anything about him. But it can't be denied that he was an ATG, and one of the best and greatest openers of all time.
Triple hundreds in a day (vs Lillee, McKenzie and Lock no less), 8 hundreds before lunch, was one of only 3 batsmen who performed well during WSC, double hundreds vs Snow, Procter and Lillee.
He was the only opener post WWI who combined an excellent technique and the ability to handle the moving ball, with the ability to score quickly. He had the ability to destroy any attack and one of the top 5 truly elite batsmen of the past 50 years.