My biggest problem with Bitcoin is definitely the transaction times. Most of my transactions are processed in around 10 minutes. The only problem is that some of the transactions take around 3 or 4 hours which is too long to wait for.
You mean is confirmation times, because transaction time is very fast.
Yeah confirmation times in bitcoin its so long more than 10 minutes for 1 confirmation, although I raise the fee it still took a long time to get confirmation.
Confirmation times isn't problem if they accept 0 confirmation.
Also, now we use OP_CHECKLOCKTIMEVERIFY/BIP65 so double-spend or Transaction Malleability Attack won't happen anymore.
Even you put high fees, sometimes a block need an hour to get confirmation, so you're being unlucky in this case.
Whats the drawback of accepting 0 confirmations?
With 0 confirmations, the attacker can create another transactions which competes with the legitimate transaction and the attacker can recieve his own coin back. This can be also possible if a mining pool with a significant portion of hashpower mines the double spend transaction. Only one of the transactions can confirm. However, there isn't any significant downsides when accepting 0 conf transactions. Afterall, credit cards can still be chargedback after several weeks or months and counterfeit notes can also be accepted. The probability of double spend can be decreased to a negligible amount if:
1) The shop's POS system connects to different geographical nodes and ensure that the transactions are seen.
2) The transaction has a good fee/kb.
3) There is no competing transaction.
4) inputs to transaction are confirmed.
Of course, coins can still be reversed if the attacker have 51%+ of the mining power.