Our development life cycle is quite slow/cumbersome with crappy in-house compilers that are on life support... yeah it makes a big difference not having to deploy between each iteration and get local feedback while I'm coding.

I cannot elaborate more than that but it is a bit more hairy than I described. My own tools alleviate some of the problems (sadly not all of them). Doing the best I can with what's available to me (basically building workarounds for shortcomings of our systems where I can see holes).