We used Kicktipp for the Bundesliga pool and I didn't like its point scoring system very much. However as the website interface is quite simple and useful I liked it very much. Registering a few more websites doesn't create a big problem as much as it seems.
Is there some other scoring system other than 3 points for a exact score, 1.5 for a close score, and 1 for a simple score? This can be interesting as it is possible that with a different scoring system, other guessing strategies will be more profitable.
It's possible that using multiple sites isn't that hard, but it seems to me that the chances of forgetting to make a forecast on time are higher than using one platform that constantly sends you notifications. Will see.