This amp has really sound quality , neutral side and wide soundstage . It could have a little more bass with bass boost switch but no complains here since i do prefer a neutral sound to get the natural performance from my iems. Battery is great , i still haven't charged it yet . I like the volume knob it is very easy to adjust . The output could be a little easier to use. For example when using my pk1 it demands some force to put it , and get it out of output . The size is portable but could be less bulkier. These are just very minor details but the conclusion is that for the money , this amp has amazing sound quality , amazing battery life and best of all the best support you can get with Gary being a very friendly persons that offers lifetime warranty for his product , either if it is your fault or not
 
Honestly what else could you ask for ? 
 
Very happy customer here 

This is an amazing ultra portable amp. I paid 99$ for it and couldn't be happier. 
 
Sound
This amp has one of the best soundstage i've heard for this price , if not the best. The soundstage can easily improve with the switch ON . The detail is really good , and with the bass boost switch which also boosts treble a little bit , the detail and clarity is even more improved . There is another switch as well for higher impedance cans to give more juice but i rarely use it for my IEMs. 
 
Portability
Ultra portable , this amp is extremely small and comes with a case and all necessary accesories as well with a wall adapter to charge the batter within 6 hours instead of the usual 12 hours needed for amps.
 
Design
I would prefer the volume switch to be bigger so that i could easily adjust the volume , but i understand the logic behind this , since it is a very small amp and wanted to keep that size.
 
Price
This is a great amp for the money