I think there are pro's and cons with both airlines in C/J.

QR Positives

1. Seat very comfortable, but depends on what aircraft turns up
2. Food in business class first class
3. Lounge in Doha excellent
4. Crew attentive from europe via Doha
5. Business Class 2x2x2 gives a spacious experience

QR Disadvantage

1. Often change their planes 2 weeks before departure i.e. 777 to 330
2. Bump people off flights without notice
3. Ground Crew are terrible
4. Difficult to contact/change flights
5. Less attentive outside europe
6. Entertainment system difficult to use on 777
7. Entertainment system not extensive

EK Advantages

1. Staff attentive
2. EK Lounges except Dubai are excellent
3, ICE best entertainment system in the air
4. Bar at the back on A380 excellent
5. Good selection of wines

EK Disadvantage

1. Seat tight,EK need to drop arms electronically to give a more spacious feel
2. Business Class 777 2x3x2 layout makes cabin feel very small.
3. Starters and dessert excellent, but main course often poor.
4. Bus Seat on 777 does not extend out far enough in cradle position.
5. Dubai lounge not good in the mornings, not enough seats/toilets,
6. Lack control at gate
7. A380 service very slow, need more staff on full business flights

So for me QR in the air wins hands down, but i will stick with EK for now until QR ground services improve.