We recently purchased SB Chat from LivePerson and I have to say I am quite impressed by it. We switched over from phplivesupport to this new system which is java based.
If you provide chat support to your customers, the design of the system is very well suited for that. The operator program is designed to allow multiple operators to easily handle and pick out multiple incoming calls. With phplive, we use to get frequent disconnections due to timeouts, no such issues so far with this system.
It's priced towards the higher side, $150/month per active seat. However you can get a good discount if you are buying several seats.
I don't normally recommend products but this is definately worth its price.
Regarding your past experience with PHPLiveSupport, you said you got disconnections and timeouts. Which version were you using at the time? I've talked to them over at PHPLive about this and they said that there were issues with a previous version, but the current 3.0 product did not have this problem any more.
Well, the current 3.0 version as well did give us disconnects, and was less than impressive.
We've had absolutely no disconnections since we have adopted this new package, and we have always appeared online to our customers 24x7x365. That was not the case with phplivesupport, there were times where we appeared offline to customers when staff was actually there. I had to asked the guys to relogin to get us to appear online again.
A really nice thing about SB Chat is you can supervise your support and sales staff realtime. Sometimes we are handling 5 or 6 simultaneous chats and honestly, I've not seen a package that handles it better.
Here is a screenshot of the operator program. I have greyed out sensitive information. The list of visitors you see is a live list that is generate by java code in each of the pages. So the list is very accurate and allows sales to proactively engage potential customers.
Edit: Seems I cannot get image to appear within post, so i have uploaded it to a different domain (not our's - as not to violate forum rules) to allow for direct linking http://www.iamit.us/lp2.jpg