Without wishing to be rude to the Spanish, a Spanish IR is quite simply not worth the paper upon which it is written. We see quite a few people who've gained a Spanish IR and, without exception, they are a long way short of the sort of standard that is required.
When it comes to renewing an IR in the UK they ALL need a serious amount of remedial training, very few have been taught the correct techniques in the first place. Of course, the IR holder thinks that he got a good deal in Spain because he got a first time pass - usually being blissfully aware that he would not be able to pass a UK IMC rating test.
I am staggered when I see posts on here which seem to indicate that the choice is being made based upon how smart the website looks - if you select your training provider that way, then you get what you deserve!