Hi Corte,
I'm sure that fellow users will chime in with first-hand experiences soon. π ... In the meantime, let me please clarify some points regarding MIR Pro.
First of all: MIR is capable of creating a wide variety of natural acoustic enviroments, be it an almost dry studio setting (a nice example here), a classical orchestral hall (example here), typcial scoring stages used for film scores (example here), or highly evocative, mystic surroundings (a great piece of music here). The most important decision is to find the MIR Venue that fits your needs, therefore.
Second: Within a Venue there are usually up to four main individual microphone array available, each of them in a different distance from the actual stage. It's important to understand that _moving_ a Main Microphone by hand from the back of the hall closer to the stage will just change the decoding geometry, _not_ the IRs themselves (... which means: even if you move the Main Mic forward by 20 meters, the sound of the room wil still be the one form the back of the hall). You will have to select another set of IRs by chosing a different Main Microphone to get a closer sound. - Most of the time, this will be Mic 1.
Third: You have several ways to change the relation between the direct signal and the actual MIR signal within the application. You can do this either for each "Icon" on a MIR stage individually, or by using the global "Wet / Dry Offset" feature in the Output section of MIR Pro. (The latter is most likely the feature you should try first, right now π ...).
Fourth: If you like the sound you get, but find the actual reverb length to be too overwhelming for your taste and needs, just use the Reverb Scaling slider in the Output section to shorten the overall reverb length of a MIR Venue.
Fifth: A bit more advanced, but very effective nonetheless: Try to use a different Main Microphone setup instead the default setting. If you want to hear less "space", then it's always a good idea to use virtual microphones that don't pick up so much sound from the back. A good choice would be the "M/S Stereo with Cardioid M", which is available form the huge list of pre-configured setups. - (BTW - the other extreme would be a Blumlein-setup consisting of two crossed Figure-8-capsules: Here you would get as much room-sound from the rear as you get from the front.)
Finally: It's obvious that features like the optional Secondary Microphone inside a Venue or the use of MIR Pro's algorithmic reverb add-on ("MIRacle") will make the overall mix sounding more wet, not more intimate. Make sure that you aren't using them unintentionally.
... maybe these points can give you some input for the successful use of MIR Pro. π
Kind regards,