Would a eel prefer longer or wider tanks?

[HAAAAAAAA]

I have a tessalata which is quite big i would say about 3 and a half feet long and i was wondering if it would prefer a more longer tank rather than a wider tanks which the eel is currently in

The tank my tessalata is in, is a 210 gallon (48 inch long, 34 inch width, 30 inch height)
And connected to a 60 gallon planted (macroalgae tank) he is currently the only one in the 210 with the whole system being about 270 gallons

I wanted to move him to a 150 gallon which I reckon would have more space for him to move around since it's (60 inch long, 24 inches width, 24 inches height) he will be the only one in the 150 but the whole system would be a total of 280 gallons because underneath the 150 will be another 130 gallon planted tank which will be connected to the 150

So any thoughts regarding this?
I feel as though he's more cramped in the 210 become he can't swim as long as he wants because it's only 48 inches long and in my opinion i think that he would like a longer tank

 

[littlefoxx]

I feel my eels like the length more so they can fully stretch out and swim when they want to! My tank is 300 gallons 8 feet long