Possibly, I am certainly more into developing than domaining so mini sites is not always for everyone but I have mini sites made within the last month doing $1 a day and mini sites from last year doing xxx per month.
I have reg'd traffic domains as well but would they not be better monetised with a mini site rather than a parking page, that is the point, if you have traffic then move straight to better income and also possibly increase traffic? if you dont, a mini site could help you get some traffic.
I bought a traffic domain domain last year for $4500 from SEDO and put a quick site on it which increased the traffic a good bit and soon paid itself back completely and I have now sold the domain this year for $15000, the buyer was only after the domain not the site on it, but couldn't ignore the traffic that I had generated and had to pay accordingly to take it off me. In fact as they only wanted the domain they have left my site on the domain after the sale WITH my adsense so that they dont lose the traffic while they develop their new site so it still ears every day just now for me
I would say traffic domain + mini site is even better.