I've got a pair of the sig 150's and they are great boxes! For the price, bit over $60 shipped, I feel they are a great bargain for price per watt.
That said, as roxy noted above, they may not fire as low as you would like, and they are pretty large. If you use your mini out and about you may want something smaller. I've got a couple of the istick 30's and an istick 50, and the 50 has fantastic battery life. If you want to move to removable batteries and stay with a mid budget, there are lots of options like the sigelei 30 watt box or 50 watt box, or the ipv mini series that will be much more mobile than the sig 150.
For fixed batteries, the itaste MVP is touted to have great battery life, but I can't vouch for that.
I do not have an evic-vt but i was playing with one in the local vape shop, seems like a decent mod.
All that said, if you don't care about size, the sig has been a strong performer for me! It fits perfectly in my back pocket as well without falling over, very comfortable.