I've been watching Love Live School Idol Project and Love Live Sunshine. Both series had two seasons and both series had the same basic storyline of a group of students trying to save their school from closure by becoming School Idols and winning the "Love Live" contest which they hoped would make the school famous and more attractive and increase applications.
Despite the two series being so similar in format they production studio managed to give each series its own identity, both had an good and interesting cast of characters each with their own personality.
The songs were quite decent too. But unlike other music based anime the characters were members of a song and dance troop rather than a band, this I found made quite a nice change.
Overall both series had good storylines which were sufficiently different and didn't come across as obvious duplicates and I enjoyed watching both series a lot more than I thought I would, but on balance the ending of 'Sunshine' was more believable.