I am a big fan of the original.  At the time the grittiness of the scene, and how it affected individuals and society was compelling.  To this day my friends and I will quote lines from Trainspotting.
I thought the new film was OK.  Not great, and not bad.  It paid appropriate homage to the original, and it had moments I felt were quite good.  But for me it did not have the impact that the original did.  It may simply be that in the interim, the rest of society/films caught up with the harshness of the original, or that I have become less sensitive to it as I age, or that the story was just not nearly as compelling as the original.
7/10 for me.  Worth a watch for sure on a plane or if you are a fan of the original.