iFast exchange rate is not great, at least based on GBP to USD conversion (sell GBP for USD) that I checked this morning, between 9-9:05am
Mid market (Bloomberg) around 1.3308-09
Zing 1.3305 for small amount no fee, 1.328 with fee - still the best rate all around but obviously no more Zing in 1 month
T212 1.3286
Wise 1.327
Revolut standard no fee 1.3266 (/ 1.3355 if sell USD for GBP)
iFast 1.3234
HSBC GM 1.3209
So iFast exchange rate is worse than all the usual e-money suspects.