If you are fishing from the bank, the most useful choice will depend on the depth of water in front of you. The closer the water depth is to the length of your rod, the more difficult life is. The exception might be if you are willing, or able, to use a sliding float.
However, you do need to take into account the extra headroom a longer rod needs. Be wary of overhanging trees. If all your favourite spots are tree lined, a longer rod might be a problem. Fortunately, I've not had a big issue on much of the Trent that I've fished. It's also worth bearing in mind that you may need a longer landing net handle to use in conjunction with a longer rod.
There is one other plus point for longer rods, particularly on rivers, like the Trent, where the prevailing wind is downstream. Float control can be far easier with a longer rod in less than perfect conditions.