Despite ZA is a very simple (easy to understand) firewall, I think it has much *issues* and problems. Also that much bells and whistles like a bloatware suite...
I think that statement crosses the border into FUD territory.
For many users, ZA has no issues, or problems, is stable and works well, including me at the moment.
I have had issues with ZA in the past, but I have had with Kerio/Sunbelt and Comodo too: no software is perfect.
I honestly don't know what you mean by bells and whistles: ZA Free has no unnecessary features.
Bloatware? ZA free includes the option to install the pay version. There is a very clear option to decline. ZA is a commercial company and they want to sell you one of their products: that's their right.
They also make available a free firewall which has been one of the most respected products in the area for years.
Let's try and give some unbiased advice to people rather than the latest fashion, please.