There's actually a big difference between all the different designs of inlet, they all direct the airflow over the air flow meter in slightly different ways.
Some are well designed and give a smooth flow over the meter at all flow rates, some are poorly designed and at certain flow rates cause hesitations and poor running at certain rates... We tried quite a few different designs before settling on the one that gave the smoothest and most consistent flow.
I've mapped up some of the cheaper variants which are basically just slash cut (no smooth bends) which are a disaster to the MAF curve and also remember that the larger the pipe i.e. 80+mm the lower the resolution and higher the chance of poor running. This is less of an issue running either SD on Cobb or hybrid MAF/SD on Ecutek but is still well worth considering.
76mm (3") give enough scale on the stock MAFS for about 720-730hp, so enough for a basic hybrid turbo setup, if you're pushing further, either 80mm inlets OR HPX MAFS OR just run speed density tuning (best option really)