Software is the main issue rubbish auto focus miles behind the competition if your shotting mountains that dont move its a great option
More the fact that I understand most are rebranded Tamrons. I imagine they're not up there with Canon L, Sony G etc.
How many lens do you need? Looks like they have quality lens at most focal lengths. Google FA lens.
The Pentax K1 looks great, but the lens lineup puts me off.
Thanks for posting and welcome to htukdeals