Of course, simply because two casinos are both safe, reliable and licenced, does not mean they are equally good. Casinos have many different offers when it comes to games selection, number of games, lay-out, ease of navigation, number and type of live tables and more. Some differences are very subtle and insignificant and do not really affect the overall gameplay of a casino. Other differences may simply be a matter of taste, for example casino design. Some people prefer a simple, dark theme that does not distract too much from the gameplay. Others prefer a colourful, fun theme full of animated characters.
On the other hand, some things make a real difference. Some casinos offer huge bonuses for example, where as some do not offer any at all. That can make a huge difference when it comes to choosing. Another thing that can be a determining factor when choosing a casino is the offer of games it has on tap. There are several major game providers like Microgaming, Playtech, NetEnt, IGT, Nextgen Gaming, and Yggdrasil, each with their own style and selection of games. Plus, there are a dozen or more smaller providers. If you like a certain game or game type, see who the developer is and if the new online casino you choose offers games by the developer.