I've been back and forth to MAN from BNA several times now on DL 64/65 through ATL. The first time was on a newer 757 with video units in the seatbacks. The last 3 trips have been on older and tired 757s which weren't as pleasant either way. I have at least 3 or 4 more trips that I'll be making this year to MAN.

I'd like to try a new route or skyteam affiliate, as I continue to build my skymiles balance. I admit I am not too eager about going through JFK though.

Would CO through EWR offer nicer equipment? Any others?

Welcome to FlyerTalk!!

CO is the only other one-connection routing. They only run ERJs on the BNA-EWR route, so that is something you'll have to suffer through for a couple hours to get up to EWR for the onward flight. They operate the EWR-MAN route with the 757-200s. Right now ~13/41 of the 752s have AVOD throughout the plane, as well as power at all seats. The non-AVOD planes have emPower plugs in the front half of the plane (exit rows to the front, inclusive of the exit rows). CO is continuing to upgrade their 752s and expects to have the entire fleet converted by the end of the year. I do not know the schedule for DL's conversions.

All the other options are double-connects, which I don't think is worthwhile.

Also, if you are buying cheaper fares the CO flights will only earn you 50% MQMs for your DL elite status, which would likely prevent you from making PM and getting free lounge access in ATL/EWR on these trips.

Ahh, that does make a difference to me then. Guess I'll be sticking with DL then as I have an investment there. I don't mind the EJRs on the EWR run, but for the overnight trip I wanted something a bit more enjoyable.

I've not had any major problems in/out of ATL in terms of delays or customs. Would it be worth the effort to try JFK or should I stick with what I know?

I would suggest looking at the prices/fare classes for your upcoming trips, and if there is one on CO in a fare bucket that gets 100% MQMs, try them out. You'll need to avoid Q, I, S, W, T, X and L fares for the 100% MQMs.

I wouldn't trade ATL for JFK. I think that ATL is more reliable and reasonable to connect in. Plus the longer TATL flight gives you a better chance to actually sleep a little and arrive somewhat rested.

A double connection means more miles, so I would go for that.
KL, AF and OK all have plenty of flights to MAN from their respective hubs. Moreover, if you fly OK and have some time to spare, you may well be able to grab a free stopover at PRG (most fares allow it, as long as you get a ticket on OK stock).

In a nutshell, you would be foolish to trade an ATL connection for either EWR or JFK. Both NYC area airports are subject to frequent ATC flow control delays and ground holds.