I'm someone who went back to school and what I suggest is that you take advantage of the knowledge you have learned. I would recommend looking at programs and see which universities have courses/expertise in things you actually want to accelerate your own learning. Going to a B university to take courses/be around students that are learning from an expert in a subfield is just worth it more than going to an A university or an easy university just for a Master's. I'm sure there's plenty of other personal things you have to balance but I am happier with my education mainly because I went to somewhere that specialized/had experts in things I specifically wanted to get better at where as if I took the 'easy option' I would have been less happy with the time spent v. personal growth.
Also if there are particular courses you want to take it's worth contacting professors who have done that course in the past and make sure they don't have a sabbatical/retirement coming up. While this may not guarantee anything I have seen people disappointed by ending up in that situation where the particular lab ended up working on a major project and the number of courses available for master's students was less.
You need to have a plan for what you want out of your Master's and then choose to do it in my opinion, just assuming a Master's is going to take you to the next level betrays the fact that a Master's degree is usually a first tier true postgrad specialization, where a doctorate would be a second tier, and postdoc/principal researcher/etc would be what I consider a third tier of specialization. You have to do the due diligence to understand what you are signing up for.