One of main reasons I bought RSSEO subscription for the second time is it's SEO performance and Keywords tools.
I was satisfied with them, even though I always thought that they can be easily improved.

I wasn't using RSSEO for a while (since end of 2012 and Joomla! 1.5), when I came back and checked its functionality on my Joomla! 2.5.18 (with RSSEO 1.0.0 r17) website hosted on my own VPS I was unpleasantly suprised.

SEO performance tool keeps giving all my competitors and me Google page rank "-1" even though most of us have Page rank 1-5.
I thought it was just temporary ban by Google, so I check it again few hours later and nothing changed, then again few days later and still nothing.
Now, this is serious bug in my view.

Keywords tool was another disappointment, because for some keywords Google Ad Preview and Diagnosis tool shows that my website is the first result in SERP and RSSEO Keyword tool shows 0.
For another keyword, RSSEO keyword tools shows that my website is on 11th place and Google Ad Preview and Diagnosis tool show that it is on the first page.
When checking positions over random remote proxies, results in SERP are the same as in Google Ad Preview and Diagnosis tool.

I contacted support about SEO performance issue and I got the famous "It is not us it is Google's fault".

I think that all these can be solved if RSSEO upsated their software or, for example, hosted RSSEO server over which all RSSEO customers would send queries to Google.
This server would have to be authorised by Google to do this queries.

On the end, I think that RSSEO is a great product and I don't regret paying for its subscription, but it definitely needs major updates when it comes to Google ranking/connectivity.