Disagree here imo it depends on the 250. I think Doha 2017 and even 2016 definitely had some value as Djokovic beat a very good Murray and an average Nadal in them (but the Nadal win was savage). Likewise for years Queen's was a 250 but often had very good draws. For me it depends on the draws and on the tennis. Masters and 250's alike only have 5 rounds and are BO3. The full field being present makes Masters much more prestigious but there can be cases where in practice the draws for lesser tournaments are more difficult.
Well we know Ferrer went through hardly difficult draws to win the events, since he hardly ever beats the top players anyway.