The Tamron is great optically: good range, bright, very sharp. However, it's biggest flaw for me is its very large size (longer than the Fuji 16-55 for instance).
Also, its bokeh seems very busy.
On the other hand, the Sigma 18-50 is bright and very compact which is what I value the most these days.
Sure, the range is limited, but at the moment I mostly shoot with 3-4 primes: Fuji 18 f2, Viltrox 23 f1.4, Fuji 35 f1.4 and sometimes the Sigma 56 f1.4.
So the range covered by these lenses is enough for me.
I think the Sigma 18-50 along the Fuji 14 f2.8 and either 23 or 35 f1.4 would be perfect for me.
Also, its bokeh seems very busy.
On the other hand, the Sigma 18-50 is bright and very compact which is what I value the most these days.
Sure, the range is limited, but at the moment I mostly shoot with 3-4 primes: Fuji 18 f2, Viltrox 23 f1.4, Fuji 35 f1.4 and sometimes the Sigma 56 f1.4.
So the range covered by these lenses is enough for me.
I think the Sigma 18-50 along the Fuji 14 f2.8 and either 23 or 35 f1.4 would be perfect for me.