I've been using one for a year, for the money you won't get a beter FT scope. New Nikkos are nearly double the price and have been suffering from quality issues for a while.
The t50 is on a par with a good nikko. Only minor issues, ret is mildots only but that shouldn't be a problem. The ret lines and dots are a bit heavy but again shouldn't cause you any problems, it certainly hasn't caused me any. Turrets could do with being a more conventional shape , but again hasn't got in the way. personal opinion is that for £400 there's nothing to touch it for FT, not even a good pre-loved nikko