Yes, we win regularly, and have the full investment. If I don't win once or twice a month, I'd be quite disappointed, even though the bottom prize is now only £25, not £50 as it used to be. It's fun, and works out even Stevens for other investments, and you can still keep your money intact. I also do the lottery each week, which is basically a waste of money, as you lose your original stake.
From the April draw, my husband and I each have 2 x £25 warrants (cheques) waiting to be paid in to the bank, but there are never any guarantees. I keep a list of which bonds have won, on a spreadsheet just for interest, and one of my bonds has won twice.....