I did a little lounge hopping (more on that later) so here's a mini comparison of the temporary lounges at GLA.
Lomond lounge
Nice choice of seating, good lighting and power points.
Hot food served until 1600 and it was replenished very quickly when I was there.
Last orders at the bar 1630
Closes 1700
Any flight departing after 1700 will be sent to the Upperdeck lounge - this applies even if your flight leaves only slightly after 1700 and you would have had to leave to get to the gate before the lounge closes!
Unlimited drinks, prosecco included. Champagne is an upcharge.
The naan was replenished as soon as I took the last piece.
Upperdeck lounge
Lit like a school cafeteria and about as charming.
Tokens for 4 alcoholic drinks per person are handed to you as you enter. I've not had to hand over tokens for a drink since Camp Bloodhound (and it was more welcoming than the Upperdeck!)
Prosecco and champagne is an upcharge. To be fair, the Laytons Champagne may sound like a budget offering but the Champagne house is part of the Lanson Group and the product is certainly not terrible. £17.50 for a half bottle is very close to what you would pay for it in a wine merchants.
Very limited wine selection (a pinot grigio and a chardonnay were the only whites)
Draft beef wasn't working when I visited
Supposedly has the same food options as the Lomond Lounge but nobody seems to replenish the food so only some curry and very dry rice was on offer. I got told off for lounge hopping from Lomond to Upperdeck "I'll let it slip this time but don't do it again".
Other people have reported moving from one lounge so another so no idea why I was singled out. Neither lounge has it's own WiFi and relies on the Glasgow Airport WiFi system which needs an email to login so have a disposable one ready.
I can't wait for the real lounge to reopen, I miss the pies 😜
The menu was the same as the Lomond Lounge (in theory) but these were the only dishes actually on offer.
Classy!

Edit to add paragraghs back in - they went AWOL in the first draft.