London Heathrow transit
Our arrival gate was at the end of a pier so a decent walk to flight connection centre. I didn't mind for it is good to stretch after sitting so much. There was a short wait for the bus for T3 to T4 transfers - it arrived about 5 minutes after the time indicated to next bus for T3 to T4. The bus ride itself takes nearly 10 minutes. At T4 security queue was short so I was soon back airside and went straight to the lounge.
Qatar Airways has a non-standard lounge access eligibility - first and business class passengers can use their Premium Lounge at LHR while elite passengers in economy class get to use the Skyteam lounge at LHR. (Similarly at DOH the main lounge is only available for first and business class passengers.)
As with Emirates lounges that are for both first and business class, the food and beverage catering is better than you'd normally get for a purely business class lounge on other airlines. ^ I also had the option of visiting the Malaysia Golden Wings Lounge (at least until their flight departs) but it was an easy choice to skip this.
I'd arrived just as the last morning flight was boarding, and the first afternoon flight was not for several hours. Thus at the start of my lounge visit I was the only passenger, ably served and heavily outnumbered by the staff.
I had a long transit so plenty of time to shower and freshen up. The shower rooms are pretty good although perhaps not the best amenities. I like the area by the clothes hooks is heated so your clothes are nice and warm when you get dressed.
I also had plenty of time to sample some of the beverages on offer. After a while I got bored and was feeling rather sleepy so went for a few laps of the terminal to stretch out and hopefully waken up. My laps included going out all the way to the end (and back) of the victor pier. I still have nightmares from when I'd get horrible transfers with departure gate way out there - those gates are a good 10+ minutes walk from the main part of the terminal along a sloping and twisting passageway. This filled in the time nicely.