I have two points / views on this -
1 - The companion flights are worthless, every time I have tried to use them, it has worked out cheaper to buy 2 cheap / sale fares instead of one at full price then the taxes on the companion, these should either be scrapped or changed.
2 - The upgrades are great, I use the white card on online shopping (also double miles at xmas) to buy everything from holidays to ebay, I also use it at tesco 600 points for every £2.50 in clubcard vouchers. So I accumulate the miles very easily for my upgrades.