I use the Square Reader at Crafts Faires, both with my iPad and iPhone. The iPad needs a wi-fi connection. My iPhone works via my Verizon account. If you actually have the card in your hand the % the Square takes is pretty small and I get the payment in my bank the next day, If you don't have the actual card and type in the #s say from an email messsage or over the phone, the % they take is much, much higher. I don't know the actual % since I do not accept cards that way.
I would say at a crafts faire 40-50% or more of my sales are via the Square. It is really great. I know for sure I have lost sales until I was able to take credit cards. You can set the sales tax at what ever location you may be and it calculates everything for you. You can even set up you own list of items with prices, photos, etc and just click on the item . This is great if you have many of the same items. I sell origami cranes at a Sandhill Crane Festival.
The chip reader is still a problem sometimes if my customer does not have a chip card. Several times I have had to ask them for another card. So far so good. My sales have soared since I have the Square at Crafts Faires.
A couple of times I have had customers whip out their own cell phones, log onto their own PayPal account and send me $ on the spot. I check my own cell phone and get an email from PP saying I have $. Then we complete the sale. That works very well too if the customer can remember their log in info for their PP account.
One note about PP... if you have a customer who wants to pay that way, if you can have them send you $ ask them to do it via "Send Money Via Friends & Family". That way YOU do not have any PP fee at all. The customer does, however. I have made sales this way via my website. Those PP fees are really high if for example you sell a painting for $300 +.
I hope my experience has helped.