Cicero's 'Laelius' is not an easy read so you have my sympathy if you have to wade through it. I can only give you a general answer as it is many years since I had to wade through it myself and am in no hurry to repeat the experience.
You will probably find many observations on friendship in 'Laelius' that we would still subscribe to today, such as the statement that true friends will hold each other in high esteem or the argument that true friendship will be strong enough to survive or adapt to changing personal or public circumstances. However, the idea that friends will be perfectly agreed on all matters, which is part of the definition of friendship in 'Laelius', would strike us as odd today. Of course friends will be like-minded on many matters but we are mostly capable of remaining good friends with people whose opinions and tastes differ from ours. Indeed most of would find our social conversation very dull indeed if our friends agreed with us on everything.
I am sure you will find similar examples in the text of things that still hold true today and of other pronouncements - and doesn't Cicero like to pronounce? - that seem very old-fashioned and irrelevant to our times. Good luck!
As i read "Laelius on Friendship", i was mostly struck by the differeneces between what Cicero described and my experience with friendship in modern day. He focuses on the main point that friendships between those condsidered "perfect" and "ideal" men, are unrealistic and non-existent. Instead, Cicero asserts his opinions about friendships between common and everyday men. However, his views are extremely hippocritical; Cicero holds himself in a higher light than what would be considered the common man of Rome. He talks of virtue and goodwill and how true friendship only exists between good men, and by good men i think he means those in his social circle. Cicero does make a couple points that i agree with: he states that friendship is a relationship of equals, that there shouldn't be submissive and dominant side, but mutual affection and attatchment.