Can I use Google Play Services geofences to get location profiles without a service running all the time?
The AutoLocation add-on for Tasker allows you to do this. It makes use of Google Play Services Geofences, and is put out by one of the most reputable Tasker add-on designers around.

To set it up once you've installed Tasker and AutoLocation, create the geofences in the AutoLocation app and click start geofence. Then in Tasker you can set profiles to start from an Event. Choose Plugin, then AutoLocation, then Geofence, and set up the condition. Be sure Tasker is enabled (if the app icon in the action bar isn't coloured, long-tap it). Tasker does have a foreground service (always-on notification) by default: you can disable it from Tasker's preferences.

One shortcoming of this technique is that AutoLocation's geofences only create events in Tasker, not contexts, so you can't have settings changes automatically undo themselves when leaving the geofence.