I'm 4/24, and I've considered it. Here's my own thinking:
- We also have in our household wallet, 2x CSR, 2x CIP, CIC, CF, and I'm planning on getting the CIU for DW. Between these 5 card products, that's a pentafecta for earning bonus UR on pretty much every penny of spend going forward. And with high cost of living in the Bay Area, that's a lot of URs just from organic spend.
- I don't really have a plan for my last slot, and none of the Chase co-branded cards under the 5/24 rule are especially compelling to me.
- I never get targeted for better or highest offers on the United MPE, likely because I already hold their legacy MileagePlus Select, which I plan to product change but never cancel because that's my oldest credit card.
- We don't fly Southwest enough to chase after the Companion Pass.
- I could always use more Marriott points, but I'm not sure if I want to burn my last slot under 5/24 until December 2018 for the Marriott Rewards Premier Plus. I just got the CIC in May and the Marriott 100k offer is supposed to expire soon (in July), and that's just too close for comfort for me.
- Do I really want to double dip the Sapphires when my 24 months are up in about January 2019? I've gotten quite a few Chase cards this year and I'm trying to keep a low profile.
- I have 2 cards dropping in December 2018 and February 2019, but more cards that I want during that time.
- I'm trying to keep DW in reserve and under 5/24 to get the cards I may not be able to get.
Meanwhile:
- Amex has too many personal cards that I want to go after.
- I'm at 3 credit cards with Amex, out of a limit of 4 or 5. And I'm eyeing the SPG Luxury, Blue Business Plus, and Hilton Ascend and Aspire cards (probably next year after I close some in my wallet).
- I've still got to make my way through Amex's charge cards.
- Amex's business charge cards (the BGR and Biz Plat) carry too high MSRs, so they're out of reach unless I can get a targeted offer.
I'll see what the new cards and offers look like later this summer and decide what to do then.
Since you mention you have no MR-earning cards, you really should dip your toes in. MR transfers to ANA and VX, and there are some sweet spot redemptions to Japan on ANA through
Virgin Atlantic.