I'm just now getting into aggressively going after points/miles, so I think it's time to re-evaluate where I stand.

I currently have a Chase UMP Visa. Wife & I just signed up for the Amex Platinum with the 100k bonus (thanks FT!) So that puts us at 200k MR points, plus about 100k UMP miles I have currently.

I am thinking about getting either the United Explorer or the Chase Sapphire card. Is there a reason to prefer one to the other? I am leaning toward Sapphire but not wedded to it.

I often fly UA/CO -- EWR is the most convenient airport to me -- but I can pretty easily get to LGA and JFK so I'm not wedded to sticking with UA/CO. I'm considering hitting my spend on the Amexes, then getting the Sapphire as an everyday card and putting the current UMP Visa on ice (figuratively). But if this is a bad idea for some reason, would love any advice.

I'm not strongly opposed to an AA card, though they just seem not to be the best airline for me most times. I'd have no problem going with DL, though the best deal I've seen is 50k miles, which is why I figure, why not just go with the Sapphire...