I was wondering about the difference between that and "Nosotros dicíamos algo"? It turns out that there is no real difference if a) the action is not habitual and b) the action is truly past. In that case, native speakers prefer the continuous imperfect over the simple imperfect.
"A New Reference Grammar of Modern Spanish: Fifth Edition" (Butt and Benjamin, 2011, Ch. 14 Section 5.5)
Otherwise, the continuous is more precise than the imperfect, giving either the impression that the event was happening right then "We were in the middle of saying something" or else that it was something that happened over and over again. "Siempre estaba hablando de su familia" (He was always talking about his family.)
(Ibid, Ch 15, Section 2)