Audiologist here! All Paradise models will have the same number of mic ports whether it is a 30,50,70, or 90. In the picture, you are comparing an M series to a V series with the V series being quite a bit older. Each Series, P, M, V, B etc will have a different “form factor” which is the case.
The difference between the 70 and 30 models are:
The 70 has 6 categories used to categorize your environment, the 30 has 4
The 70 has speech in loud noise and speech in 360 degrees, the 30 does not
The 70 has ultrazoom advanced, the 30 has ultrazoom essential
The 70 has echoblock, the 30 does not
The 70 has tap control, the 30 does not
The 70 has stereozoom, the 30 does not
The 70 has windblock, the 30 does not
The 70 has soundrelax, the 30 does not
The 70 has real ear sound, the 30 does not
If you don’t know what all of those features are, in summary the features above help the 70 be more clear with better understanding in more difficult listening situations, especially in background noise.
Hope that helps!!!