Enanthate* This type of test has a long ester, results will start to appear around week 4/5, Ive used it at 500 mgs and it was too much for me, I gained around 25 pounds in a 14 week period, it also made me bloat but my six pack was always visible.
TBH I would reccomend that you go no more than 400 being 250 your starting point, ive stack the test with halodrol and proviron and used a spark of masteron for 5 weeks (I wished I used it longer)
Not sure if test solo is worth since you can stack it with more compounds that could add extra benefits (like an oral or a faster acting ester like prop) but if you do I would recommend aromasin dosed at 12.5/25 EOD (test dosage dependant)
Test solo expect around 10-30 pounds (depending on your goals and diet) and of those gains i would say with confidence that nearly 40/60 percent would be quality gains.