Grand Palace in Riga is a wonderful hotel
Following your recommendations I stayed here. They gave me a free airport pickup, and since I was arriving on a private flight I expected a mistake but the driver was there and waiting, gave me a free airport return too, equally fine.
They do pay attention to leaders Club. I was upgraded to a nice two room suite, and given a fruit basket and a bottle of the unusual Latvian Balsam alcoholic substance.
The main restaurant was perfectly accommodating when I asked for an all-wild-mushroom dinner to reflect the seasonal passion in Latvia. It was excellent and they charged only 7 LAT, truly cheap for superb cuisine. They discovered it was my birthday and gave me a double of my favorite single malt, as well as a fine bottle of white wine with my dinner. I found out these were comped only after I looked at the bill.
The staff were impeccably courteous and efficient.
The hotel is not cheap, but nothing much in Latvia is. It is, however, very good value. When considering all the extra consideration I had it actually might have been less than I would have paid at a lesser hotel; I simply do not know.
The location is as good as it gets, only a block or so off the main square. I would consider no other hotel in Riga.