My personal preference would be to either trim it back substantially or replant the plants in the middle to one side of the tank. While you do kind of have an opening for swimming, I don't think it's big enough. I try to move my plants to the edges of the tank and keep the center of the tank free of plants (unless they are short broadleaf plants for color). This allows A LOT of fish to escape off to the side while the swimmers have a very wide open space to swim, you also have a wider open space to place food and it won't get all tangled up in the vines. I think it's just aesthetically more pleasing as well to have them off to one side, then to have plants just sprouting everywhere. While they may sprout all over in the wild the fish can always swim on and find an area with fewer plants. Most of my plants are floating plants (much loved by my fish) but I keep them all pushed to one side of my tank, leaving about 1/2 covered in thick plantings and the other half open for swimming and feeding. You can also put the plantings on opposite ends and leave the center open - whatever you think looks the best AND is most useful for your fish. I think a large number of fish want an open space to swim quickly as well as a place to hide or sleep at night.