They are totally different from each other, different led, different output, different beam distance, different UI etc. But if you are talking about IF25A vs EC01, at least they both use Anduril firmware, max ouput is 3800LM (6500K) vs 3500LM.
IF25A has 6500K (70CRI) and 4000K (95CRI) to choose from. If you like extremely bright flashlight, choose 6500K; if you like neutral tint and high CRI, choose 4000K.
As for the quality, you need to know EC01 and IF25 are made by the same factory.