There's more than a couple of downsides, however. First of all, you have to play your free spins BEFORE starting to play with your deposit or bonus funds, meaning you can’t use these as a kind of “second chance”, and because all winnings obtained from free spins have a 60x wagering requirement attached to them, those extra fifty free spins are all actually going to contribute to additional wagering requirements you have to beat before you can make a withdrawal.
In my case, I was “lucky” enough to hit a full screen of explorers during free spins for the first time ever whilst playing with these free spins, landing me with the kind of obscene wagering requirement that nobody but the luckiest of players is ever going to have a chance of beating. I made a valiant effort for sure, and played all weekend with my £150 of deposit + bonus funds and several hundred pounds worth of free spins winnings, but in the end the math got the better of me and I finished up with a big fat zero after dreaming all weekend of making a nice chunky withdrawal from a measly £75 deposit.
Of course, your mileage may vary and I’m sure some players have had more success playing with this bonus. But the whole way the deal is set up is, in my view, intended to ensure that as few players as possible ever get any kind of return from that first initial deposit, and personally I find that to be very unfair.