We have two children, 7 and 2, and they have a bunk bed. It's the kind with a staircase (with drawers in the stairs) up the side, instead of a ladder.
Safety is a HUGE issue...I had to design and build and swing gate with a lock and attach it to keep our toddler off the stairs. It's ugly, and I hang a blanket over it, and it's a bit sad because it's a beautiful bed and the staircase is beautiful and yet I had to make and attach a door. :( However, that solved our safety issue. A ladder would have been MORE of a problem, because I wouldn't be able to block it from our two year old.
Sheet changes on the bottom are no problem, but my 7 year old has to get on top to help me change her sheets and it's a pain in the butt. She also has to make her own bed (which she would anyhow, but still) because I can't get up to do it.
After all that, would I switch to a trundle? NO WAY. In my opinion, they are a mess, one child doesn't get to have a bed during the day, and if you leave it out you might as well just get two twin beds. I think a trundle would be a bigger hassle than a bunk bed. :(
I did see a corner bed I wish I had bought instead...it was two twins, with their heads meeting at a cube that would go in the corner and serve as a nightstand for a lamp, etc. I didn't see this until afterwards, and even though it would've taken up so much space I really did like it.
Check out bunkbedking.com for ideas. I bought our bunks there, with free shipping, and don't regret it.
*****UPDATE****** I also want to address your issue with not having decorative wall space. Each of my children have their wall decorated. My seven year old, over her bunk, has a HUGE American flag with Native on horse, and over her head side has all of her wall decals of planets. The ceiling sports her glow in the dark stars.
Under the bunk, around my toddlers mattress, are her wall decals of Sesame Street characters. They are plenty big, and there was plenty of room to do them up in a nice way. I imagine she'll soon outgrow them, and I'll change them to something else, but I LOVE laying on her bottom bunk because it's so cozy, she is surrounded by little characters she likes, and a lot of my decorative style comes in with the duvets (SHAUN THE SHEEP!) and cute, brightly colored pillows. Of course, on top it's Dinosaurs. They don't match, but it's a huge splash of color and I love it. :)
***And I know the rattan one is precious, but they will outgrow it literally within years and I can't imagine spending a grand on something that would only get a few years use...and would probably be so broken down at that point that you couldn't expect much on resale. Rattan is not a sturdy material. To me, this looks like something in a guest room that never gets any use, not a comfy comfort spot for children. :( Sorry...I know...