Kmxu

Here is information from gcmap.com. The choice really depends on your preferences. If you cannot tolerate extremely long flights, you break up into two relatively long flights through NRT (choice one below). If you really prefer B787, you get on SFO-SIN and and perhaps NRT-KUL. If you fly economy, you really need to make a good choice on aircraft seat types.
Good luck.

3 segment path:
TPA IAD 020° (N) 025° (NE) 811 mi
IAD NRT 330° (NW) 340° (N) 6,753 mi
NRT KUL 236° (SW) 244° (SW) 3,357 mi
Total 10,921 mi
4 segment path:
TPA ORD 344° (N) 350° (N) 1,011 mi
ORD SFO 272° (W) 276° (W) 1,846 mi
SFO SIN 301° (NW) 288° (W) 8,446 mi
SIN KUL 301° (NW) 301° (NW) 184 mi
Total: 11,488 mi
3 segment path:
TPA EWR 026° (NE) 032° (NE) 997 mi
EWR HKG 352° (N) 004° (N) 8,065 mi
HKG KUL 213° (SW) 216° (SW) 1,575 mi
Total 10,638 mi

1kBill

What class are you flying in? If C/J, I would go TPA-SIN-KUL. Lots of UA PQDs & PQMs and UA's 787 in C is tolerable. Unfortunately no UA Prem Y yet to SIN.

If Y, I would avoid flights on anyone's 9 across 787 or 10 across 777, forgoing UA PQD's. Those seats are are just too narrow.

jonisflying

truncated

If you're flying in J might consider the connection in NRT — NH now has their long-haul lie flat J seat on NRT-KUL, and EWR-NRT and IAD-NRT (from October) both have guaranteed Polaris if you want to stick on UA metal for the TPAC sector

Kacee

Agree. If UA PQD/PQM are desired, this would be my routing.

dkc192

Personally I have a strong distaste for the late evening NRT-SE Asia flights coming off a long TPAC daytime flight, where my body just wants to crash against my will, given the flight arrives around midnight and I want to get on local time ASAP. So personally I'd vote for either of the SIN services (though UA29 might get you in too late to make a same-day connection) or the new overnight SFO-HKG (UA877) and forego some PQM/PQD on the way out.

On the way back, again I have a preference for avoiding NRT, though this applies mostly in situations where I'm headed to the west coast. Given that itinerary, I would want to get a proper night's sleep on the TPAC leg. However, as a non-morning person, I have a hard time fighting off sleep on the early (7-8am) departures of the SE Asia-NRT flights, which then makes it difficult for me to get a good night's sleep on the TPAC. Going to the east coast, I wouldn't mind doing a KUL-NRT-ORD/EWR-TPA (where you arrive in ORD/EWR in the late afternoon), as you (1) have a longer TPAC for sleep, and (2) arrive much later in the day and can therefore get by on a bit less sleep.

Kacee

I also prefer the late night US departures, but am not a fan of the UA 789 to SIN (and especially not at UA's uncompetitive fares). Whether UA will offer a connection via HKG is always hit or miss; and it will not be competitively priced. At the prices UA charges, I at least want a decent product, which you'll get via NRT.

On the return, the morning Asia departure works great for me. I sleep pretty much the entire TPAC segment, and arrive SFO in the morning well rested. The late Asia departure messes up my clock for a week.

jonisflying

Thank you all for the great responses and ideas. I'm trying to plan a December trip, and this all helped a great deal!