What does PayPal do well? PayPal is such a simple way to accept online income for your business or services without signing up with a merchant service company. All they need is an email address to send it to, and both your client & you feel comfortable because PayPal is trusted and well-known.
What does PayPal not do well? The only issue I've had with PayPal is when using it to purchase/spend. Also, I'm not sure it's even something PayPal can control. I paid for an item on an online shop which I didn't realize was outside of the US. I was then charged to my bank directly for the international fee. I didn't mind being charged, as it's a standard, but the payment went directly from my bank account and was not reflected on my PayPal activity, even though that's where I made the purchase from. It took me a while to hunt down the mystery charge.
What do you wish you had known about PayPal before using? I have no complaints or surprises. PayPal has always easily met my expectations.
Have you used a competitor to PayPal? If so, how does it compare? I have switched to a merchant services company due to lower transaction fees, but as stated earlier, for a freelancer or someone just starting out, PayPal is excellent and helped me get my business off the ground by accepting "credit cards" and money digitally.