I purchased eForm because it is so much cheaper than the alternatives and has a lot of features. I primarily wanted it for creating logic based multi-page forms.
Most other form plugins are very expensive and have a yearly cost, so it seemed to be a much cheaper solution than Gravity forms or formidable forms.
Although while the one-time cost of eForm may seem cheap initially, bear in mind you have to renew your support every 6 months if you ever want to contact them about anything, even to just report a bug.
So unless you never need support and never need to contact them, it doesn't actually work out quite so cheap when you consider this.
They also do not respond to direct emails or messages on Facebook or any form of communication except tickets, which you cannot do unless you pay for support.
I contacted them on facebook a few times and it took them over 1 year to respond to the first message. Still waiting for a response to the others.
I ended up having to pay for 6 months of support just to report a bug, which was very annoying, you shouldn't have to pay for this.
As many features as the plugin does have, it is also lacking a few very basic features, which become more noticable and annoying over time.
1. lack of customisation of the emails. There is a lot of unnecessary info on the email that is not relevant to most people and cannot be removed and you cannot change the design much.
2. the layout of the emails is also problematic. If you have any form submissions that contain quite a bit of text in any of the fields , this really messes up the email as it causes the columns to be be squished down so small they are unreadable.
3. If you have a "subject" field on your form, you cannot use this as the subject of the email. This is posisble even on free form plugins.
i don't want to list out every annoyance I have found, I think you get the point.