Rizla, you need to know what the temperature of the coolant coming out of the stat really is (thermocouple or similar slipped inside the top hose), the gauge/sender are notoriously unreliable (although in most cases changing the sender like you say you have usually fixes that...) IMO the bottom hose being cold with the new stat is a red herring and kinda suggests to me that the old stat is opening too early and letting coolant flow round the rad earlier than it needs to, warming up the rad with "warm" water. Are these tests being done with the car standing, or after a drive (to get proper heat into the engine and coolant)?
Mine will sit on my drive running from cold for ages without the fans running, in this cold weather I fancy they may never come on, the rad is sufficient to cool the water enough in these conditions, engine idling on the drive.
The stat should be open around 88-92deg.C to let water into the rad, that is way too hot to hold on to with your hand - if you can hold the top hose with the old stat when it is open, then it is open too early at to low a temperature.

I keep emphasising your reliance on the gauge indication of temperature - mine used to sit at about 1/4 on the gauge all the time, from 5 minutes after the engine started until the fans came on, which is obviously nonsense, periodically it would go up over halfway then come back again while driving... - just illustrates the unreliability that's all I'm saying. Changing the sender did fix this by the way, so that it reads mid way normally, and a tad higher when the fans cut in.