You know that muffled fit you describe, sounds like what professionals call occlusion. It doesn’t have to be this way. Some of the modern aids, including offerings from Starkey can include an IROS vent, which is basically a big hole that stops you feeling so blocked up. Modern feedback reduction systems compensate for this ‘hole’ and allow the vent to be a lot bigger than they used to recommend. So you may not have to go for an open fit to lose that problem you’ve been experiencing with your old aid.
A ‘few years’ ago when you got your old hearing aid, the tendency was to make the vent as small as possible to reduce the danger of feedback. But new technology has really made a difference here.
The number of manufacturers is not as big as you might think. If I were buying today, I doubt I would look any further than the big boys: Oticon, Widex, Starkey (Audibel), ReSound, and Siemens. You should easily be able to find at least three of those brands well represented in your area.
But demand that after you have been tested you get to listen to a real hearing aid. In fact, when you book the appointment you should be asking if the hearing professional will be offering this. Anyone who doesn’t let you listen to a real digital hearing aid is frankly, too lazy to be any use.
Also demand a free 30 day trial with no penalty if you return the aid. Any decent office will give you this.