Always had wooden runs but this is much better. very safe and secure, looks good and is of a high quality. My run is for guinea pigs and it will be great to have their hutch in there, leave it open, and just walk in to see them. I bought the 2 x 2 x 2 but wish i'd bought larger as I want to extend it already, only thing putting me off is unclipping all those clips!!! I put this together myself which wasn't to hard at all but I did it over 2 afternoons as wasn't in a rush for it. Only reason for 4 stars is the rather high price!!!