FYI-Carnival is getting rid of plastic deck chairs. The chaise loungers are likely here to stay and will all be replaced en mass ship by ship. The plastic furniture is cheap, and is also a hazard if there is a fire, therefore the Triumph, Conquest, and Liberty all have metal/canvas (and or other fabric/wicker) chairs on the Lido deck and balconies. I can't speak for all other ships in Carnival or other cruise lines, but hopefully one by one each ship will change. The Miracle has nice wood deck chairs (from looking back at pics from 2007).
I am not fan of rubbermaid plastic chairs, so I agree with you when the cruise lines keep them in favour of better deck chairs. The new chairs are not light, they are very sturdy. I can't comment on the quality of chaise lounges as I can't sit in a lounge chair for longer than 15 minutes before realized I have something better to do than fry my skin, which burns crisp in under one hour with sunblock 45 on.....
2007 Victory & Triumph
2008 Conquest & Liberty
2009 Valor, Freedom, and Splendor
2010 Glory and Liberty
I gotta go where it's warm.....
Over 40 victim of fate.....