Tren is generally considered good for spot injections. My last tren cycle I rotated between bis, tris, delts, and quads, and my arms seriously never looked better than during that cycle.
I think the less of any kind of ester (time) that exists in the gear being used the better is for site injections... This would be the reason people like to site inject winny for that purpose , I believe.
Yes, it's one of the best for site injections. If you can take the smell, crush up some of the pellets in a mortar and pestel and mix it w/ some DMSO and apply it transdermally for good site growth.
I have noticed significant growth in some areas I have been spot injecting. Specifically, calves and bis, which I have gained about an inch each. This could be totally coincidence and may be independent of the site injected. I really don't know. I guess I go by the "can't hurt might help" school of thought.