I love text based RPGs too. If they have good mechanics. P:T had awful mechanics.
A lot of properly written text is good for my immersion. Also, I find isometric games very immersive. I played Entomorph: The Plague of Darkfall today and I got very immersed in it. I don't think I would get so immersed in it if it was FPP, because I don't find FPP RPGs immersive.
To me most important features are:
1. Works on my computer, 2. Good mechanics and interface, 3. Good setting and story, 4. Good writing, including good quests and dialogues, 5. Aesthetic graphics.
Personally, from some time I treat technological level of graphics as something that is completely unnecessary for my enjoyment of game, but makes game not work on my computer.
I loved the Arcanum setting, graphics, dialogues and mood, but I hated its mechanics, so I didn't even finish it because they made playing it a chore.