Function: The helmet has a slot for an SD card (32 GB) on the side, it's also one of the features that differentiates it from the T2S (with FM radio). Call Pickup used once (it's not why I bought the helmet), but the microphone works well, and I understood well the other person. The Bluetooth works fine, fast connection, no break, no sizzle.
The headset can be connected via cable.
Comfort: I have struggled to position the helmet, but it stays in place and no pain despite the helmet a little greenhouse. I have not yet had the opportunity to wear it more than 2 hours in a row and I do not wear glasses. The leatherette cushions, the helmet is made of plastic (for the price, so do not expect better). This is an on-ear headphones (does not cover the ear).
Sound: As well tell you, this is a helmet with a lot of bass, some like it, some not. Feel free to use the equalizer.
Battery life: I have not recharged and given some of the comments (about 20 hours of listening), announced the 45h is not totally wrong.
The T2 + is for me a good Bluetooth headset for the price.