Avaya IP Office SoftPhone ? WTF ? Don't, don't, don't !!!

My occasional rant about software, today Avaya software ...

I don't know what happened here, but I have been kindly asked to install some software written by complete utter n00bs.

1. It only runs on Macs or consumer OS's (Windows) - great for a softphone, remember though, that it is the type of software you are supposed to install on your "workstation" - Tablet ui's are for consumers, imho. What about Linux ?
2. It does not remember your settings, as in, how you sort your contacts ... WTF? Seriously ??? The contact list is clogged up with built-in groups and default contact sort is alphabetically, regardless of who is online or not.
3. It clogs up your Windows registry by creating a node guess where? HKCU\Avaya - this is BAD PRACTICE, it should be under HKCU\Software\Avaya, but wait, they have a node there, too ... utter n00bs. Imagine every software company did that ...
4. Their server runs on Linux as they claim better TCO, gossh, at last one thing they got right, what about the client software, though ? It would allow their customers to decrease their TCO even more, don't you think ?
5. How about smartphone support ?

In the end, I assume we got it because they have good hardware phones ...