yes, it does take some money.
However, is it "massive?"
e.g. in 1997 I had a pension fund worth (lets say) £100,000/
During that year, it had capital growth of 5.7% (it was a bad year) and in 1998 it had growth of 32.3% (a good year)
There might have been charges of about £1500 in each of those years.
Let's suppose that the dividend yield on the equities in the funds might have been £2,000 per year.
On this, there would have been a notional tax of 10%. So that's £200. When the pension company stopped being able to reclaim ACT, my pension lost that £200 per year.
Compare that to the £1500 charges.
Compare it to the £5,700 or the £32,300 growth.
The £200 is so small as to be virtually undetectable.
"Massive" my arse.