T200 works great I've done about 6bottles over the past 1.5 years. Every bottle was short by .5 to 2 cc. No complaints here though the stuff works and it is cheap. Great with dbol.
Technically, underdosed means less than 200mg per cc. Underfilled means less than than 10cc per bottle. T200 has been known to have a little bit of both problems.
i have 3 bottles coming on monday, so i can let you know if they are underfilled. as for strength i have no idea but i've heard around %10 less the 200mg. i wish i knew as i am going to take 400mg with 200mg of cyp and 50mg clomid everyother day for 10 weeks.
as for pure Mass T200 works excellent. I use it during the winter when I do my 2 shots of it and 4 - 6 dball for 3 weeks and t200 for 6weeks and get great results. Water is great and that is another thing that T200 is great for.
if you're talking underfilled my first "10ml" vial was only 8.5 for this cycle. heard it's between 10-20% underdosed, or 160-180mg/ml. However I have had a few 10cc vials.