For security reasons then choose coinbase over jaxx.
If you like security, then you keep absolutely all of your coins millions of miles away from any online wallet. Using Coinbase you could get Goxed for all you know - with Jaxx you can't. And Coinbase are a giant target for hackers and inside jobs, whereas a personal wallet is not (especially if you use a paper wallet and don't spend).
Also, Jaxx will give you a million more coins.
Jaxx can give you problems with the interface, but they're just that. With Coinbase all you can see is the website, and it's terrifying to know that something much worse could be happening behind the scenes.
Someone said coinbase is too large and goes down, and I want to ask why is it big? It's merely because many people trust them and the workload is too much but that doesn't mean they aren't good.
Or it's because:
1. They're incompetent and can't use decent servers despite their outrageous fees
2. They're manipulating customer funds.