The dragon eel has 14 RHD. This is bad, as we all know. Fortunately, they're dragon RHD, which makes them quite a bit better.
Ability scores are meh. 26 strength and Large size aren't that great on a 14 RHD creature, 21 constitution isn't notable either, and the other stats are all in the 8-13 range.
30 ft. blindsense is a non-ability. DR 5/adamantine and +18 natural armor would be nice, but defensive features are worthless without the offensive presence to make yourself a target. Improved Grab and Swallow Whole are pretty standard as far as monster abilities go: useful on the few foes that are puny, easy to attack, and incapable of teleporting and weak against almost anything else.
Finally, dragon eels get Powerful Charge as a bonus feat, which is something at least. It's not like 2d6 damage per attack is anything impressive: scouts of all things get twice that, but it's free.
Considering the overall unimpressive chassis, lack of limbs, large amount of RHD and inability to function on land without magical aid, the dragon eel is deserving of -0 LA in my opinion.