Hi there been a Construct 2 and 3 for a while now... im out of my C3 license, but i will renew probably if im going to start to make games again.
Here is my input on PROS and CONS posts that you find around this forum.
Majority of the posts are made by frustrated users that had technical advanced issues on big projects, or projects that were not even supposed to be made using Construct "default" capabilities.
And when i say technical advanced issues, i mean majority of the problems on CONS are server side stuff... for projects that were not meant to be made in Construct from beginning, but because Constructs interface is so addictive ... people still try to overcomplicate things... even though simpler would be to just pick notepad and use the coding language of choice.
And i know most of C3 users don't know code... but those CONS and PROS are from people that know how to code... yet they still using Construct cause of its ease of prototyping... don't fall for their issues.
On the other hand, there are also some of the pros and cons posts made by users that didn't even tried to understand Construct's way of doing things and just dissed it.
In short you have to buy it and see for yourself, but if you played around with the trial version, then the premium version is like that plus the extra stuff that in trial are locked.
Now Construct 2 and 3 are different ... C2 is not going to be updated anytime soon as the team is focusing on delivering a better more powerful product C3.
About exporting... the beauty of Construct 3 is that simplifies exporting to platforms as compared with Construct 2 that requires manual export/compilation through a third party.... to deploy on android or ios.
Construct 3 is ready to use and deploy MINI GAMES out of the box, on any platform, and with incorporated wrappers for android and ios i think... i don't know for ios ... never done ios games/apps.. but only android.
Very intuitive and lots of tutorials + manual available.
Sure there will be some glitches as the engine is in development, but if you aren't an advanced user don't worry about it... it won't interfere with your needs.
And ... don't fall for the Construct 3 is simple to use and lets you develop games easy i can build the next AAA MMORPG with it, Construct was never meant for AAA Games.
People need to look at Construct/Stencyl/GameMaker and other similar engines as Wix like platforms for making games.
They are good to prototype and even deploy on small scale, but when it comes to serious stuff and upscale your project they fall apart.
Lucky for you... i doubt you will build the next MMORPG or the Next Clash of Clans/Lineage/Fable etc with it... So sure buy it, have fun with it is 11$ a month ... or 120$ a year (i pay more for a landing page hosting server a year) ... if is not what you need find another one and you didn't lose anything precious but your time... and some pocket change .... if is what you need then is a good investment.
As for the performance stuff... is more of how you make the game logic ... and for the "if the user "will notice or not" you made the game with Construct" is a nonsense.. if it works nobody cares what you used... they are there to play your game, not check your programming skills.
Hope my input helps, i would have written more about it, but the post is already long and i don't want to keep you reading something to convince you on anything that really is more of personal usage and choice ... and also this subject was asked and answered since Construct was made, you will probably find the same answer in other posts as well ... Is been 12 years in the making almost... lots and lots of things have changed, and the engine matured in some parts, and in some parts still needs to grow.
But for a beginner need, it will be doing the job. Have a great day.