A number of players don't like how stiff the GHS's feel, but that's what I like about them. The LaBella's might be a bit less stiff, but are in the same neighborhood. LaBella makes a 'low-tension' flat but I've never tried them. Maybe better for a fretless.
I have the Low tension flats on a few basses and I like them. It's a different tone than the DTF's but still good IMO.

