The entire process of using Coinbase is seamless. All you need to do to start buying/selling Bitcoin is link your bank account to Coinbase, and if you provide a credit card as a backup payment method you can start buying Bitcoin instantly.
Coinbase works by connecting to a US bank account. This makes the service easy to use for Americans, but unfortunately does not let Coinbase work internationally. Also, connecting bank accounts to a online service does have additional security risks.
As you're typically dealing with locals, transferring funds is typically free & fast and the site lets you see what bank a given user is with. There are no other fees for buying/selling coins if you're not advertising.
The site is very intuitive and depositing dollars was fast and easy. The whole process from on-boarding to buying my first bitcoin with them took about 2 days. When I sold my bitcoin, the withdrawal landed in my bank account on the same day. Also, support is super helpful and very friendly.