Been here many times and slowly deteriorating. But
I have stayed here when it was the Milton hotel, then Menzies hotel and now Hallmark. It hasnt changed much in any décor way or set up reception, pool gym and rooms etc. but over the time the change of ownership has tightened its belt. What i mean by this is they have had to make small savings and put prices up where possible (i suppose all businesses are doing this now, if they can). However the main thing i noticed was the quality of the towels in the swimming area were a little over-washed and overused and the price of food here is very expensive - on par with a very good restaurant outside. Which is where I would recommend you to go.
Saying this if you don't use the pool or eat here then this is a great hotel. Parking is safe opposite and wherever you want to be in Glasgow the taxis are all very cheap and friendly. Which you can order from reception. It looks like the location is out of town, but with the SECC about 15 min walk and Central railway stn about 20 mins at the most and a plethora of restaurants in and about town of a variety of styles, Mother India, Mr Signs, Indian Choaphara Thai and the mussel inn (my favourite). Book it you wont be overall disappointed.