How similar are boot sizes across brands?

I had rossignol rental boots at 27.5 (quite smaller than my usual shoe size) and it fit me perfectly (it was a old version of the HI SPEED RTL MV 120). They were racing boots at 120 flex. Now I want to buy hybrid boots, the Alltrack Pr 130 Lt Mv Gw, and I am wondering if the sizing would be similar/the same.