I did a run just now and here are the observations:
Gnome Tinker. Preps: Platemail, Patches, TT altar (didn't know it doesn't work), nothing (maybe should've been extra glyph), Quest Items, Knockback Mace, Whoopaz, Burn Salve, Fortitude Potion, Compression Seal. Few misses there, but some had no obvious better choices, and some were just wrong.
Patches was a horrible choice and he cost me way too many resources.
Topside - I found a spellcaster kit in the shops, and the gold subdungeon, which was nice. I might've converted too many Glyphs too early, and should've conserved my resources better, but it turned out pretty good alltogather. I bought Martyr Wraps, Battlemage Ring and Elven Boots right away and misused my compression seal on the Knockback Mace (there were better options). There was a Mage Plate Which I saved for later and probably shouldn've - the extra mana would've come in handy, seing as i also had Elven Boots and the Pedant of Mana. And conversion for Mana Potions.

There was also a Poison Ward which in retrospect I should've bought right away - not doing it cause me a lot of pain.
First Floor - Bandits, TT and Fine Sword - Probably the best possible early floor, got GETINDARE (which I kept around forever), got Tiki's Edge right away, got Poison and eventualy Dodge. Cleared it Easily.
Second Floor - Vampires and Dracul - Gravy! I ran out of hp potions thanks to patches and the vamps, so I joind up with drac right away, and proceded to get some sanguine and the resists boon. I eventually took one level of Lifestal, and a few Blood Swells here and there. Dracul's sanguine antics probably make him the best possible deity you could find, after TT who makes or breaks any Gaan'Telet run (IMO).
Third Flood - AA's and Pactmaker. I used Pactmaker on a quick consensus (not sure if it was the right thing to do in retrospect), and I cleared AA's with relative ease thanks to mana potions, Drac, Knocback and Poison. And huge ass, Martyr Wraps and Battlemage Ring fueled Fireballs which had them losing DP's in 2 shots. I converted the Knockback Mace afterwards, but I only saved a small slot due to the Compression Seal missplay. This is a big deal in Gaan'Telet, but on the flip side, the AA's could've been on the 9th floor and I'd be lugging a useless large item all that time.
Fourth Floor - Snakes and Earthmother. I remembered I had a Poison Ward in the shop when I was on my last snake. Damn. This probably lost me the run, but that would become obvious much later.
Fifth Floor - Desert Trolls and TT. Fireballs and Poison, not too difficult. I think I may have used the burn salve at this point to get un-corroded.
Sixth Floor - Illusions and JJ. Found the Orb thingy right away, smashed it for 5 bloodpools and descended with a nice chunk of exploration left.
Seventh Floor - Druids, the Troll and Mysteria - breezed through it and got 2 Mana Potions for my trouble. Things were looking good.
Eight Floor - Goblin Miners and Binlor - killed it. I had a nice routine of fireballing 5 times with a mana potion and using GETINDARE for the win, but I arsed it up on the last guy and got manaburned with no comfortable way to get un-mana burned. Ended up converting all but one Bomb (which might also've been a mistake because there was still some topside exploration left). Leveled up in the end just before I descended, but not before buying the Mage Plate to get around 28 mana. I was almost completely drained of comfortable resources by now.
Nineth floor - Goats and Taurog. Well, Taurog was useless, and the Goats did me in. I had plenty of blood pools and Drac Piety, but HP was useless, and I had very little stuff I could part with to convert for Mana Potions. A also converted a CP-less GETINDARE thinking it was the real one. Damn. Ended up converting to EM and killing the Goat after two Clearances, which is when I noticed that they must've changed the desecration rules so I couldn't get out and go back to Drac.
Final Floor - I stumbled in fromt of Horatio completely drained of anything but Mage Plate, Fireball and the Whoopaz, and hit him with it just for kicks. The fukker still has mana burn and 50% res both. Damn.
Conclusions -
End game bosses with mana burn - still suck and mandate Soul Orb. Which was always my biggest grievance with Vicious Gaan'Telet. And if one of my million Tinker shops with Quest Items prep happened to have Soul Orb it would be a non-issue. which sucks majorly, and makes me surly, unproffesional and prone to profanities.
End game bosses with 50% resist both and 5000 HP - can only be tackled even by completely decked out casters, if they happen to be on the same floor with Mysteria. Which, again, sucks, because there was nothing except chipping at him with a piercing wand which would've helped me kill him with fire even though I could've had - Mage Plate, Elven Boots, Mana Pedant, Battlemage Rind and a 10+ stack of Marty Wraps Corrosion. Oh, and I even had access to a flaming sword at one point.
The AA floor - could really use to have the AA's not spawn in the corners. And I have to remember to abuse burning more next time.I completely forgot you could hit a full HP guy and still take a DP off a burning no-hp guy.
Dracul - is possibly the only reason a got this far, and is broken in ungodly ways. Possibly only in Gaan'Telet, but still. TT for the Poison, possibly a very early Taurog, and then Drac for the win.
Binlor - seems like a complete waste of an altar regarding what floor he is on.
EM - Is a decent last ditch effort if getting 10 mana can really get you out of a scrape. I'm not sure there's a reliable way to get out of her with the way Desecrations work ATM.
Martyr Wraps - work globaly and are broken in ways beyond ungodly ones. Probably anywhere, not just Gaan'Telet.
Stupidly lucky Gnome Tinkers - make for awesome spellslingers. I'd use them more often if there were any Tinker Quests.
QUESTION:
Did anyone in fact beat the place lately, and if so, how?