Waterproof on the outside: will not be so great when you need airflow - waterproofing layers block out most of the wind. Additionally, we have not come across any affordable fabric that is waterproof + abrasion resistant. Most fabrics, like Cordura, require the waterproof layer to be fused to them.
Waterproof layer built-in: again, most of the airflow will be block out. the wind will be blocked by the liner and not reach you skin
Removable waterproof layer: requires you to take off or zip in the liner depending on the weather
We have been looking into this for a long time and it seems like for most people the versatility is more important than anything else. People want one jacket that can take them through all 4 seasons, or rather one jacket that can take them through any weather during a long distance trop. To provide that versatility you need removable layers.
You want to wear a warm shirt because its cold, but you don't want to take it off when the temperatures drop! With time, i am sure fabrics will developed that can achieve all we want in an "affordable manner, but currently the choices are limited and compromises have to be made.
What I am trying to say is.. our suit will have two removable liners and can be worn five different ways:
• shell + waterproof liner + thermal liner
• shell + waterproof liner
• shell + thermal liner
• Waterproof liner only. Our liner will be one piece rain suit by itself and can be worn without the main shell.