Warlock of Tiamat

I am building a level 10 Dragonborn warlock, standard array, 10str, 12dex, 14cons, 8int, 13wis and 15 char, with racials str to 12 and char to 16. I am going with pact of the chain, taking eldritch invocations agonizing blast, eldritch mind, gift of the ever-living ones, investment of the chain master and voice of the chain master. for ASI's was thinking instead of maxing out on char to take feats ( dragon fear and gift of the gem dragon ) this would put me at 18 on char. DM is letting me have a rod of the pact keeper which will put me at +9 for spell attack and spell dc at 17. thoughts? is it better to max out my char with Asi's?

It is the same issue every adventurer must face. I think be at max lvl 16 everyone should have their primary stat maxed or 18 but the hardest choice is picking when because it isn't as flashy as feats but if you fall behind on it then it becomes detrimental. i personally would go with the feats because you have the rod to cover your slack a bit, however i think its also good to look at non-racial feats as well. This is just me personally, do what you think is best always.