UKH

About 20 years, I had a thermostat inflatable mat and since 2012 ish, I’ve been using a Z lite for all types of camping, whether it’s with the family or up in the hills. 
Anyway I’ve now after something a bit more luxurious so probably another inflatable. 

Are thermorest still the best brand out there? Let me tap into the hive mind for recommendations? 
I’ve had a look at some reviews and it seems some can be a bit rustley so ideally not one of those as I’m a light sleeper 

TIA

Light sleeper...me too and so rustley mats are out. I use an Exped Synmat and find that quiet.

My other mat is a Z Lite! 

You can't go wrong with thermarest or exped (if you can stomach the price).  My neo air is truly rock absorbing and a great sleep, but yes, a tad rustly.  However, not enough to bother me too much.

Well you can always use a super thin super cheap yoga mat and it'll be so much lighter and in cold conditions add under it a cut off section of bubble foil insulation (7m*0.6m for £15 in Screwfix) that'll be better insulation and still lighter than a thermorest self inflating mattress. Thermorest were good back in the day, but all I can say is "crampons!" and "heavy".

Ear plugs. I'm a light sleeper and with ear plugs I have no issues with the rustley fabric on my thermarest.

Their recent models have changed quite a lot from back in the day.

Not sure why you'd be around your thermarest with crampons on unless alpine climbing in which case you probably wouldn't have a thermarest anyway.

As for heavy, neoair x-lite regular=350g

3 season warmth, probably not much heavier than your suggested set up and massively more comfortable. Spendier though!

Exped mats are really quite luxurious, and also (can be) sensibly light. I have a Synmat Hyperlite and highly recommend it, particularly as it's the only sleeping mat that I've ever owned that easily rolls up and comfortably fits inside its stuff sack even when rolled haphazardly (ie when rolling out of your sopping Scottish bivi in a rush to get moving and get warm).

That said, the previous ones were all Alpkit; maybe Alpkit aren't very good at making stuff sacks?

I have a Thermarest Uberlite for mountain marathons but for everything else, I use a Mountain Equipment Aerostat Down 7.0 Mat Wide which is heavy, expensive, quiet, warm and soooo comfy.