I could never keep a layout for more than a few months. I find the planning and implementation of new ideas for plants and aquascaping one of the most appealing attributes to this hobby/art. It's a form of evolution, honing our skills, learning from our mistakes - an ever changing, living art.
For me not changing an aquascape every now and again is like an artist painting one masterpiece, then stopping because it looks good. The aquarium is the canvas, the plants the paint, the equipment the brush and the we are the artist. This was the subject of great discussion over on APC actually.
Keep at it Neil - one day you'll be happy, using pure logic the more layouts you have the more likely you will find anything like contentment. Chasing Amano though...... don't forget his photography (and apparent manipulation) gives the viewer a certain positive "falseness".
Good call on the L. arcuata.