Bill,
I think 30 years has probaby treated Dallas very well, from a public golf perspective, though not disproportionately to comparable cities like Houston, Atlanta, Phoenix, etc.
From everything I've read, I think the City of Dallas municipals were in pretty rough shape until the recent renovations. Both Tenison and Cedar Crest received $3 million renovations at the turn of the decade. I prefer Tenison's layout and conditioning, but a weekend twilight walk at CC is only $18.
There are several other decent municipally owned courses in the metroplex that followed the Sherill Park (Richardson) model, like Indian Creek (Carrollton), and Texas Star (Euless). Added to that are some high quality development courses like Castle Hills, and The Tribute that have public access. Cowboys Golf Club is a hybrid in that the city owns the land but the course operates as a resort/high-end daily business.
Should you pass through town with ~4 hours to spare, I'd be happy to reintroduce you or anyone else to Dallas public golf.