You can love it or hate this design of the "professional" version of the U90. It is quite impressive and one of the widest organs - but electronically the same spinet organ as the standard U90.
Here you can find a detailed description of all her functions, that I won't repeat now. Additionally my small impressions:
Rock solid, after 25 years everything works fine. This might be the reason why it is so difficult to find a service manual - because it is almost not needed
nearly no noise at the outputs!
the sine filters are not of the expensive type, you can still hear the rectangle generator as the basis. Technics used only 3 sets of sine filters per tab, the higher tabs (<2') even have got only a single filter.
the upper manual has 7 divisions which can sound in parallel, which makes a big sound, (the lower: 5 divisions).
I counted 5 Phaser/Celeste/Chorus divisions which can work in parallel also. The Leslie imitation is unfortunately rubbish.
the drum machine sounds funny. Own rhythms are easy to arrange, even with preset patters. I like the rhythms variations and the accomp. voices (filter gating!)
... in the meantime sold, as I did with all spinet organs.