The game seems interesting, but i think OMSI will still be the leader in bus simulation. Before OMSI, i played CBS2010 and BCCS San Francisco, i enjoyed both of them, specially the last one which allowed you to easily create your own custom routes within the huge map of San Francisco.
Then in 2012 OMSI came to my life, and it basically threw any other known bus simulator to the trash. The graphics were much similar to the aforementioned games, but the level of realism is unparalleled. Despite being a game developed by two amateur developers, with unstable perfomance, bad graphic engine and lots of bugs, it grew to Jupiter's proportions. Today, there are gigantic OMSI communities worldwide. Thousands of addons. Lots of people enjoy this game for hours. OMSI is the closest you can be to driving a real bus. I even think if you drive well in OMSI, you improve your bus driving skills in real life even when a lot of us wont drive a bus ever.
Personally, i liked buses since i was 3 years old, if not even earlier. There is a bus line which runs in the street where my house is. Despite living just 5 blocks away from one of the most important avenues in my city, my neighborhood is a quiet place, with vast majority of small houses and just a few tall buildings, generally low traffic... and a bus line. In the general peace, the noise of the buses are so disruptive that you hear them coming from 2 blocks away. As i grew older, i kept the same passion with buses. Until i started playing OMSI. This game made my passion with buses grew exponentially. Now i dont like buses, i LOVE them. Now i know practically every bus model and chassis here and some others in the world. In 2015 i went to Spain. Imagine my happiness when i saw Citaros in the streets of Madrid. The bus i've spent hours driving in OMSI, is now in real life in front of my eyes.
Love is the main word. The developers of OMSI are people who love buses. Astragon only loves money. LOTUS will be the true successor of OMSI, if it is done well. Until then, OMSI has long life ahead. Probably some people will be attracted to the multiplayer, but LOTUS will also have multiplayer. I dont think BS18 will have a long life.