UniBot vs UBot & other similar tools

Pros:

• commercial, trusted products with a good support
• have a big community behind them
• can be used by any age group because of their simplicity
• can be extendable through plugins

Neutral:

• depend on .NET Framework 4
• primarily use a browser to communicate
• they're a huge products for which are bugs discovered almost daily

Cons:

• they're too expensive
• bot execution in some cases is very slow, especially when it has more than one thread
• have the same problems with crashing like the browser
• sometimes they can hang CPU or occupy RAM intensively

Pros:

• completely free to use
• lightweight, size about 1mb (EXE bot is 3x smaller!)
• portable, doesn't require additional components to function
• minimal, doesn't require GUI to be designed for interaction with user
• fast in execution, it uses HTTP requests to operate
• native threading support
• highly customizable and extendable with plugins

Neutral:

• requires basic knowledge about HTTP protocol
• doesn't have a large community like others
• currently doesn't have a wizard for building simple bots
• currently can't be run continuously because it doesn't have optimizations
• currently doesn't support EXE bot creation

Cons:

• slower learning curve, must be careful when forming the requests
• can be painful when user interaction with a site is complex or if it has some protection

If someone doesn't know what is HTTP protocol, here is a short explanation and some notes about using the tools:

When you want to create a bot that does complex user interaction with a site, it would be hard to make it through HTTP requests because they are something that is low-level, ie. "under the hood" of the browser. The best thing to understand them is to go to developer mode of the Chrome or Firefox browser (Ctrl+Shift+I) and select Network tab. There you can see HTTP requests which are transmitted from the browser to the site, and responses which are sent vice-versa. As you would see there, they constantly appear in the list because they are most important thing for browser to function. Every user interaction with the site is translated into request and sent to the site, and every response is what you currently see in the browser (site appearance).
So, if the interaction is simple and requires not so much requests to the site, then it will be worth to create it with UniBot, because that tool makes building requests much easier than usual (which requires also programming knowledge and therefore it's hard for beginners).
But, if the interaction is not simple, then the better solution will be iMacros, UBot and other tools where you can automate the browser itself to do the interaction automatically, so that would be easier in that case rather than dealing with HTTP protocol. You could also create any bot with such tools, but if you want the efficiency in execution, then you would choose HTTP way, because you can command the requests that have to be sent and not let browser to do that and increase bandwidth or CPU and RAM usage with repainting the site interface.
Also, if you learn how to use UniBot, then it will be easy later to switch to some programming language as it has some concepts from programming (string commands and If clauses). If you're using only UBot, then you can't be flexible like in previous case where you can code complex bots in some programming language and make simpler ones with UniBot.

(P.S. Speaking about HTTP requests, how you should know which are important? Simple - if you're submitting some data to the site look for POST ones, and if you're visiting a specific place, then you search for GET ones. In a bunch of requests you'll find important by comparing a link to whom is request made with the site that you are currently visiting, and more herustic - to investigate the requests in full.)