In this blockchain system, there are a numbers of web wallet and I have beed using one of them, it doesn't bring any negative things so far, I haven't got any negative issue even security issue doesn't bother me, besides my current wallet, Bitamp is also looking great to catch my attention, I hope we will work in the coming days.
The concept of this wallet is awesome but you need to understand the vulnerability level of every web wallet with the inclusion of blockchain info wallet and i will always advise all the existing/new user of this wallet to make sure they register their wallet offline copy the seeds before turning on their internet.
That's the point I think about web wallet, but observing this Bitamp so far I feel it's kinda different from any other web wallet because Bitamp has taken some customer's favourable thing such as Anonymity, Instant transaction and the most important thing is the utmost security system. So it looks different from my perspective.