Cycle trailer for the bike and a lazy dog

We have been thinking about one of these for a while   as our dog likes to walk and occasionally run but not for long , when she was a pup  I bought a basket type to put on the front of the handlebars she took to it fine , but grew out of it rather quick,

so today it was delivered , and it looks great , after putting it together she got into it no problem , so looking forward to trying it out on the bike soon 

do anyone on here use one ...what's the pros & cons