From the IRS website:
"The IRS has processed nearly 50 million returns, about one-third of the total individual federal income tax returns the agency expects to receive this year, with almost 83 percent of those returns resulting in refunds. More than 92 percent of refunds have been directly deposited into taxpayer accounts."
As far as the definition of sizeable I wouldn't know i pay in every year. but I would guess if you get everything back that's sizeable lol 83 % of 50 million got a refund and manyyyy of those are full refunds. But EVERONE yaps on and on about how they pay taxes and blah blah blah... just sayin.