I tried the predator but found it uncomfortable and heavy - great construction for ops, but too much for civvy use.
After a year of dithering, I bought a reduced price Sabre 45 (£50). So far it's been brilliant.
I bought a selection (4!) of side pockets on eBay and used these as a modular system for different activities. The ease of swapping pockets is a bonus. I wouldn't add extra pouches to the back as the balance would be upset IMHO.
There are more "backpacky" sacks out there, but I like the Sabre as it's fine for days out and, with added pockets, can just about cope with a week supervising Gold DofE groups in the Highlands. I also use the pockets with the yoke system as a day bag when moving out of a camp for days with groups in the hills. Yokes are quite cheap on eBay and don't add too much to a load.
Hope that helps. In the end, however, it's what fits you that counts.
PS my OCD is much better since I've had it re-diagnosed as CDO - the alphabetically correct version ).
I have a Sabre 45. I would have gone for something else as I was worried it might not suit my frame (tall and to chubby by half) but it has turned out to be quite comfortable. I can't say I have done any long distance stuff in it though. It is supremely well made and I was lucky to get mine off a scout leader for only £55 (it was still flat and in the bag) apparently he bought a load in a closing down sale thinking the scouts would snap them up but they were thought of as being far to expensive even at that price!! I don't think you can go wrong with one really. They are built like tanks and I am sure I will wear out before the bag does.
I have the predator and I'd echo what ozzy said, it's a fantastic pack but you wouldn't want to walk miles and miles with it fully loaded. I got it for the versatility of all the attachment points etc. and the different side pouches you can attach. never had cause to regret it.
Hey I have been haveing the same dilemma I love the sabre 45 its sleek a good size and those shoulder and waist straps look mighty comfortable but then I saw the predator and though all that Mollie would be soooooo useful especially when I want to go on a shorter trip compress the sack down and maybe add a mollie type pouch to the front or side and when I want a longer trip I can add the side pouches and mollie pouches to the front aloes it gives you a lot more strapping gear to it options with lots of methods also you have the little built in side pockets for bottles or bits on the predator but I realy don't like the big squareness of the predator the sabre looks a lot sleeker and more civilian looking don't get me wrong I don't care what it looks like in regards to military and civilian it's just the sabre dose look better if it had Molly on the side and front and the pockets I wouldn't hesitate thanks to this thread I've seen those mollie attachments for the sabre but then I am still in two minds I will be walking long distances so the sabre ticks another box there decisions decisions