I am looking to replace my 100 weight upper fleece (8.5 oz) base layer with something less weight but not Down. I use this to sleep and hike in when cold or pair up with precip if wet and real cold.

Icebreaker morino wool 260 would be nice but I would not gain any weight savings. Is the IB 200 or 260 as warm as 100 weight fleece? Does anyone know weights of Smartwool, Wickers stuff that could save weight? REI MTS Synthetic looks good but probably no weight savings there.

Thanks