the top temp switches really make a difference, I had issues with this plane and the trident that were solved when they were updated and the top temp switch was added.
one thing I have noticed though is you really have to pay attention to the local condidtions when you fly this plane near MTOW.
durring winter here in louisville the plane will take off with plenty of runway to spare and climb smartly.
durring a hot summer day with the same load. it will take every inch of the runway, and struggle to maintain 500 fpm at the recomended climb speed of 300 knots.
compaired to more modern jets of its passenger range, it to me borders on being underpowered. so you don't have the margins of lets say a e 190 or a crj 900
however these flying conditions are one of the things that to me at least make the 111 one of the planes that I really enjoy flying.
if you want to see REALLY underpowered, try flying the trident at MTOW. taking off in RL under these conditions must have been really nerve wracking for the flight crew. :o
You didn't say which Trident you were flying. If it was the T3 did you have the boost engine running? Below 10,000ft most airspace has a 250kts max speed restriction unless ATC waive that and give permission for higher but that's usually for arriving traffic. If you are flying a SID (standard instrument departure) with a few turns then at 300 kts you may struggle to maintain the correct track due to the larger turn radius. 250 kts will give you a higher rate of climb below 10k' then you can increase your speed above 10k'. The T3 had a nickname of 'The Gripper' I believe, due to it's fondness of using the maximum length of runway that was available.
I do keep it around 250 if below 10000' feet, with the 111 when it is really hot out I might be able to get 1000-1500 fpm at MTOW. if I remember right the trident has climb speed recomended of 290 knots. I don't fly the trident as much as the 111 because like you said it is uh "fun" to get off the ground, but it seems to climb better at hight tempatures and MTOW once you get it going. I have flown both and with the 3 I do have the boost engine running.
again I know that flying at a lower tow would make this easyer, but I enjoy the challenge, and most of the flights I do are near the maximum range. I wish there was a paint of a 111 in private colors because I tend to treat it as my executive jet.
also I wonder how much the hush kits that were fitted in later life hurt perfomace.
from other sources I heard the "organ pipes" they fitted to turbojet powered 707's and dc8s cut the available power by about 10%