Which Diagnosis rooms are the best?

Or need I build all of them?

thx

I always build all the diagnosis rooms available.
Notice Cardiogram take a long check up time, but you don't need it more than 1. So as other diagnosis rooms.

You are kinda new to this game (or did play it much looong ago and didnt remeber a thing)? I clearly remember that with all tech and upgrades (+% efficency) some diagnosis rooms used rarely than others. General Diagnosis Room unlike real life used rarely.
If you think you notice that and ask - you right, that feally happen (regardless if you are new or old player).

And yet they all needed. First whats affect diagnosis is general hospital rules - diagnosis and where staff break. Cure potions efficency hqve 1-99% and to get maximum it must be up to 200% diagnoses. You can set 110% as basic diagnostic level and 200% as maximum. If you at start of campaign efficency of diagnose rooms is reduced. Need to be used all of them to reach at least 110% (less is deadly dangerous). All of them allow to get 200%. Although with maximum upgrades (researches) patients get 200% bit earlier than visit all rooms.
Diagnostic room doctors increase percentage increased after visiting room if they high skilled. Most skilled should be in GP Office's, although there low skill will get their skill upgraded faster - only if you have all diagnosis rooms and upgrades. Because at finale diagnose patients get 200% maximum and that didnt reduced by low skill (never be reduced, all doctors still a doctor just slower for lowskill ones and faster/+dianostic bonus for skillest ones) and increase doctor skill instead.

So before few very last missions you need all diagnostic rooms you can get. And since researches need to be done each mission from 0 you need all rooms at start of any mission. Only at last stages of last missions (or if you use cheats - at middle-stages of any mission) you find that you have excessive rooms. At start you always will get printer messages telling you diagnose is only xx% (73% for example) and they wait your decision what to do. If diagnose lower than 100% it decrease cure potions efficency, higher than 100% increase it if needed (if lower).

I think better start with diagnoses upgrades-researches to reach 110-200% efficency, and after upgrade cure efficency to 99%. At one point its pointless and after you see - you can check it for each patient individually and forcely send to Cure earlier - that patient already get 110+% better switch research office to cure. At other point there always 1%+ for deadly cure. And random always random. So better get complete 100/200% qnd then get 99% (there is 3rd one research that never get to the end, use cheats to find out which one and later never research it before other 4 categories).

In any case you need all Rooms. First they increase diagnosis which start at lower at beginning. After patients easily get 110 and later 200% they needed not for qualified diagnostics but for money.
Theme Hospital toilets are free. And not all hospitals have toilets free, i guess. Part of satire of this game - patients are money bugs. You force them to pay. GP Doctor can send them to more rooms to get 200% and bring you more money. Even if not required for Cure.

While toilets are free, PATIENTS PAY FOR RESEARCH ROOM which also used as diagnosis room but they KILL patient in process to increase diagnosis of other patients with same disease. You can pick patient and send them to death and get money for this from them.

Ok thx

Das beste Diagnosezimmer ist das GP's Office mIt einem Beraterstufartz d'rin; er gibt die Feststellung ohne weitere Zimmern, Aertze, Zeit, und Kost. Bessere Diagnose in dem GP's Office erhoeht ihre Ansehen, und Sie koennen mehr Menschen behandeln.

Forgot to mention you need besides every diagnostic rooms additional of psychiatric and ward rooms (ward with increased beds as much as needed). Maybe at later stage even more wards.
They used both for diagnostic and cure. And so 1 office will share querry with died patients and newcomers diagnosed in progress patients. You need two and place them next one to one.

Also you need 2 pharmacy for emergency patients. Later they come as bunch of 10 and 12. Put faster best nurse there.