We are merchants and buyers as well and use both BTC and Paypal. Here are few views:

+ Paypal can process almost any credit card around, even those ones we never heard of
+ Paypal is a system, accounting, reporting, live agents, outright supported by shopping cart
- Paypal is susceptible to chargeback even that 95% of them are just plain fraud by buyers where the suddenly don't recognize purchase of merchandise they received and are using as we speak
+ using Paypal one can buy almost anything on-line
+ Paypal has reasonable merchant's processing rates
- Paypal recently became quite pain in the ass with restrictions refusing many transactions

+ BTC brings most money in, more than almost any other kind of payment
+ It's fast like hell
+ easy to receive, check incoming payments
- shopping cart we have does not support BTC pricing and processing
- it is hard to get cash money out of it
- it is easier to get liver transplant than open account at exchange
- lately it is more steady but before it was too volatile for merchants to rely on
- still only small number of buyers want and can pay by BTC, maybe 5% of our buyers. For the rest 95% Bitcoin is still too complicated, out of reach, impossible to get account at exchange ...
- hard to buy BTC

We hope that in future 5% - 95% ratio will swing more towards BTC buyers. So far we received about 50 thousand CAD in BTC and with Paypal that net amount would be more like 48.5k. Looking from pure net perspective BTC is clear winner.
However, if would be accepting BTC only we would close the doors long time ago. Buyers with Bitcoin are still in scarce supply.