In my opinion, you probably shouldn't.

I'm with you that I'm not a fan of Aloft, and in my opinion Four Points is even worse. The full service properties are fine but nothing great (in all honesty I haven't figured out the SPG love myself).

In my experience Hilton Garden Inn is by far the best non-full service property, with Hyatt Place a distant second choice. I'm sure others with more experience with SPG will chime in but based on what you've described I would say SPG isn't the program for you.