Will hearing aids that are "Made For iPhone" and Android compatible (via ASHA) offer any advantages over universal Bluetooth hearing aids like Marvel?

It offers the ability to make Hearing Aid Bluetooth Specific settings changes in the MFi Hearing Aids section of the iPhone.  It also allows for connection to both hearing aids instead of connecting to just one hearing aid and routing the audio to the opposite hearing aid for stereo sound, not that it matters.  What it doesn't allow you to do is be completely hands free with your phone.  MFi and ASHA, you still need to speak into the phone's microphone where with the Marvel, your hearing aid microphones pick up your own voice.  

I have not identified any significant differences between battery life in Bluetooth Classic and Bluetooth Low Energy.  I have patients in both and so far I have not had anyone completely drain their batteries even with several hours of audio streaming per day.  

Yes there are much better apps! The Phonak Marvel app is unable to perform the “Find My Lost Hearing Aid” function. Perhaps a better choice would be the Starkey Livio AI 2400 which can find lost hearing aids with theThrive app and it has much more advanced features than the limited Marvel App, such as language translation. This feature allows you to have conversations with people who speak another language with a compatible Android and the Remote Mic + Bluetooth shirt clip. The Phonak Marvel app does not allow for other advanced options, available in the Starkey Thrive app, such as creating custom programs for noisy listening environments and geotagging those settings you created to take effect every time you return to that noisy restaurant with your friends! The future looks bright for hearing aids and smart phones. But there are differences between the hearing aids and their apps. The most important thing is to work with your Audiologist to ensure that your hearing aids provide appropriate amplification for soft, average, and loud speech inputs, and the settings are verified with Real Ear Measures. You should be comfortable wearing you new hearing aids and your speech clarity should improve significantly. Then the Doctor can help you learn about all the amazing things you can do with your more advanced smartphone app.

I’ve yet to be satisfied with Marvel streaming performance. As Dr. Clif points out, streaming is one ear only, you give up useful controls in the phone, sound quality is much poorer than several other brands I’ve personally worn, I’m fairly certain Phonak had to give up some very useful binaural processing features to create an any cell phone hearing aid. And if that’s not enough to steer you away from Phonak, I’ve found them to be the least capable of all hearing aids for hitting REAL Ear Measurement Targets from 4-8Khz.

If my patients have an iPhone I really prefer the MFi hearing devices at this time as they have way better apps (especially with Widex and Resound) than the basic up and down volume of the other aids that are "made for all". I also like the connectivity better, and the fact that it uses the iPhone's mic is actually much better in my opinion as sometimes too much background noise is heard otherwise with the ear level mics, although not in all cases. All in all you will likely love whatever you get but there are definitely some that outweigh others. -Dr. Elly Pourasef 

If  you are strictly looking at the Bluetooth connection to a cell phone, all products are all the same, however at this date not all are Android compatible.  There are features that are specific to each manufacturer.  For example, the Starkey Livio AI offers fall detection.  Resound has an app that offers easy adjustability and great flexibility.  Widex has fantastic music processing.  Signia offers a uniquely shaped device.  Oticon's new S series does amazing in noise.  Phonak was the first to connect to Android.  The list goes on.  You can't go wrong with any of them. 

The Phonak Marvel hearing aid is both iPhone and Android compatible with no need for an extra accessory to stream telephone calls, music, etc.   Other hearing aid companies have iPhone and Android  compatible  devices; however, if you have an Android phone you will need  an additional accessory to directly stream calls.  The Marvel is just one type of hearing aid.  The industry has several bluetooth capable hearing aids at many different levels of technology.  The level of technology truly matters with noise reduction abilities and sound quality.

Great question! The manufacturers are saying that the battery life will be much better for all-day streaming.

Hearing aids made for iphone connect via 2.4gHz which is suppose to be a more stable connection for streaming. While the bluetooth capability in Phonak marvel will connect to droid without a streamer, the connection is slightly less stable.