I sometimes think some of the information given is not useful to most readers. It is worthwhile pointing out the surflink media 2 must have been used with a different pair of starkey aids, the surflink is not compatible with the halo model itself.
I then note several users are experiencing poor music audio. I suspect they are having a problem setting up the TruLink app properly. I use halo hearing aids and have never experienced anything like it, it has beaten any audio I have ever listened to via hearing aids or headphones....and believe me in my line of work I know a thing or two about audio. When I switch the iPhone to its music app, the sound quality is so good it feels like my ears are not even involved in the process, just this giant concert somewhere in my skull! I get plenty of base when I use them. I also note, for the first time ever, I can actually hear the words being sung on a song. If you have difficulty hearing the words via the music setting, try listening in normal mode. It won't get quite as pure music but enhances the spoken word that little bit more.
As for other problems that may be causing issues, we all have different hearing loss so it is impossible to compare experiences, there are lots of different Bluetooth protocols, interference from other products, battery strength, the list goes on. My advice is therefore get a trial of the aids and play around with the settings on the app, don't be swayed by my opinion the halo is fantastic or someone else thinking there is no bass.