This is some really good feedback for devs... There are some consistant themes.
I think it may be time for a PSA or a "How to speed up the time to first confirmation" thread. There are three things you can do to speed them up
This is easy to do in Bitcoin-Qt when you send a transaction, but slightly more difficult to speed up on transactions you receive. I assure the readers here, if any transaction had fees commensurate with Paypal or VISA, confirmation would be lighting fast.
I'm certainly not proposing that people start spending $0.50 per TX like paypal or VISA, but it is a simple point. TX time varies because your transactions are competing against other transactions, and often... other transactions pay more than you (or your default wallet) are willing (or configured) to pay.
Easy enough to put a "Juice up this TX" button on a wallet app, just no one has done it yet.
For me, probably the transaction confirmation times.
... and fast transaction times 
I think transaction confirmation...
For me it is transaction times, and the inconsistency thereof.
Would be nice if there was a way to sort of 'predict' confirmation times beforehand
... we need long time to get confirmation for transaction
- transaction confirmation time, which can take 5-15 minutes most of the time.
Well transaction time for me is still something bitcoin needs to work on.
For me , the biggest problem is duration of transaction confirmation 
I think it may be time for a PSA or a "How to speed up the time to first confirmation" thread. There are three things you can do to speed them up
- Increase the TX Fee offered
- Increase the TX Fee offered
- Increase the TX Fee offered
This is easy to do in Bitcoin-Qt when you send a transaction, but slightly more difficult to speed up on transactions you receive. I assure the readers here, if any transaction had fees commensurate with Paypal or VISA, confirmation would be lighting fast.
I'm certainly not proposing that people start spending $0.50 per TX like paypal or VISA, but it is a simple point. TX time varies because your transactions are competing against other transactions, and often... other transactions pay more than you (or your default wallet) are willing (or configured) to pay.
Easy enough to put a "Juice up this TX" button on a wallet app, just no one has done it yet.