Selling some of the units actually helped improve the park - a little pride among the homeowners.

You need to make sure yours stands out among the best in order to be successful.I'd say the biggest value-add features include full-size stainless appliances in the kitchen, a coffee bar, and new flooring throughout to brighten the space and give it a new, clean feel. 

-Which amenities are considered "must-haves" or "table stakes" among the rentals here?

According to Zillow’s data, Austin’s home values are among the hardest hit year-over-year, only outperforming the SF bay area:Here are the metros experiencing the most price growth over the past year:How are rents looking in Austin?

I mean sue we don’t have income tax, and the property tax is among the lowest in the country, and we don’t have snow or earthquakes.

One notable company is Intel in Chandler who just finished a new fabrication production facility, a $7 Billion investment said to be the most advanced in the world, adding 3,000+ high-tech, high-wage jobs.Many schools in the vicinity are regularly ranked among the top in the state, there are numerous opportunities for great shopping, restaurants, coffee shops, entertainment, parks, etc.The rent/price ratios and cash flow/appreciation one can achieve especially in Gilbert (next door to Chandler) are excellent and I've helped clients purchase roughly 25 homes in the last couple years that fit the same model - relatively new (built in the last 10ish years - newer roof, newer HVAC, etc), reasonable HOA's (around $100 or less - which includes access to a community pool for tenants, front yard landscaping, playground/parks, etc), easy access to freeways, good schools, etc.

Usually that comes with higher income levels which naturally raises the standard of living among the town residence and as a result, raises the value of your asset. 

For utilities, we put something along the lines of "Utilities split among the number of occupants living in the home".

@Nick Mulligan  Those towns, along with Brockton are among the most affordable in eastern Mass. 

But, there's one obvious and glaring omission among the wall of data you've presented above: income.