Rambles: Has the mech army had it's day?

So, I was thinking. Has the mech army had it's day. I mean nidz can have drop spores with ultra-lascannon-beam-I-kill-landraider-every-day-and-then-have-a-cup-of-tea zoanthropes in and the amount of melta/las you can get in an army is getting to be almost ridiculous. Especially with inferno pistols on accurate drop troops. I do still think mech has it's place and it is still 'tough' but I think it is dropping in favour of ? I mean some armies have a specialised build like guard who just say ha ha look at my wall of steel and cannons and i still have fast troops in good transports which are better than rhinos even though they are cheaper to make and I still have first turn vehicle killing vendettas. And nidz are also weird but I don't know what the general build will turn into. I have seen some very nice semi-mech armies with say 3 rhino marine squads then 1-2 drop pod squads and 1-3 drop pod dreads I think that semi-mech may be the new mech.

What are your thoughts? thanks for reading,

Jacob.