Keep in mind where you want to word, I'm a GIS Developer that grew up in Microsoft land using Visual Studio and SQL-Server, using ArcGIS JS. Now I work for NYS in a JAVA land using Oracle and Leaflet. I have to admit while I still avoid Java, yet JavaScript and Leaflet are fun and PHP is easy for web services. All set, the college computer classes I took gave me some theory but practical use working with others was the biggest help.
Learning resources like Udacity, Sitepoint, Lynda.com, and Packt all helped bring my skills up to where I feel comfortable, without going back to school. In my case having a family means I still have to keep working and talking to some schools, they kind of looked down on Python, PHP, and even JavaScript. Many are geared to big full blown apps yet my work now is mainly focused simple web apps.
Before going back to school think where you want to be in 5-10 years. Most CS programs are not geared toward GIS Development and most GIS programs do not include programming or database classes.
Good Luck with your decision.
