full panniers or a bob type trailer

I did one India tour and one Eastern Europe tour with a BOB. It is all ok but about 1-1.5kph slower due to the extra tyre on the ground and the extra work from the snaking of the trailer. Down hill is good. On long straight descents or with not-too-sharp curves it is particular fun. The trailer actrually pushes you. Uphill is harder work but no problem if you have the gears and the time.
As you say, it is good to have everything in one big space. The airlines are not real keen but I amanged. Take the yoke off and take the wheel out.

I've toured with a trailer (a Bob Yak) and while it worked OK, it was a poor luggage solution. Problems:

1. It's much heavier than panniers.
2. The extra wheel drags, and it's a different size so that's more spares to carry, and more stuff to go wrong.
3. It reduces your braking power. That's because if you carry extra weight on your bike, the weight keeps the wheels on the floor, meaning you can brake harder and stop the extra weight. Some trailers put no weight on the back wheel, which means you've got all the extra weight of luggage, but none of the extra traction to help you stop it. Other trailers put some weight on the bike, but they still reduce braking power because the trailer still carries some. In fact a loaded tourer with good brakes can stop more effectively than a race bike because the rear panniers stop you going over the bars if you brake too hard.
4. It's much harder to get your bike on a train, plane or bus.
5. You can't lift your whole rig in one go if, say, you need to carry it up to a hotel room or a flight of stairs.
6. If you've already got panniers, a trailer is more expense.
7. If it has more carrying capacity, you'll just fill it with junk you don't need.

Now, none of these problems are that bad, but they do make trailers a worse option than panniers. Trailers make sense if you can't fit panniers, you're on a tandem or you really need to carry a lot of stuff. They don't make sense otherwise.

I realise I didn't answer your question about handling.

I was very impressed by the Bob Yak. Apart from reduced braking and the extra weight on climbs, it had no discernable effect on handling at all. I used it on surfaced roads, dirt roads, and even singletrack.

Other trailers will have very different handling characteristics, but the Yak is the only one I've tried.

Don´t do it to yourself. I am currently on tour with a Bob trailer and it has been nothing but trouble. It ruins my downhills, and makes the uphills harder.
It will push you on downhills, and can sometimes start to swerve, and when it does that it will try and rip your back wheel out from under you. I have to limit my speed. It catches the cross winds and again tries to take the back wheel with it.
On the Up it creates so much drag.
If I had the money I would just wap it over right now for a good low rider front rack and a couple of panniers. 4 panniers provide so much better wieght distrobution and balance. It still takes a bit of time to pack up and the spare tube and my even tyre you have to carry just don{t make it worth it.
Maybe try and find a better way of packing.
Tent, sleepingbag and mat in one drybag on top of rear rack, food in one front pannier, cooking equipment in the other, parts, tools rain gear in one back pannier and cloths in the other.