The web client(s) with 6.7 have improved again (on top of what the 6.5 releases achieved). I prefer to use the 'Flex' client still, over the HTML5 client for most things. Sadly, since the browsers are making Flash/Flex powered pages more difficult, the HTML5 client (or what they release next to replace it) is the way of the future.
While I was NOT a huge fan of the web client initially, I have seen how it's actually improved over the past few years. Granted, if you're locked into an OLD release of vSphere, your life is going to SUCK. Just like how the vCSA was NOT ready for 'prime time' IMO until 6.5 came out (where VUM was integrated into it, so you didn't need a Windows VM just for that).
I've seen minor glitches between using Firefox and/or Chrome (of different update versions) with the web client. BUT, I've been able to either work through those, or resolve them without losing hair (not that I have much left to lose).
Something to keep in mind, with technology, things are ALWAYS going to change. Sometimes the path to improvements is filled with potholes. But eventually, you get to the good roadways. Trying to bully a company into bringing back an OLD technology item because you're not willing to work with what they're producing now is not cool. IMO, it shows a lack of mental flexibility.
