I must admit, there is something appealing about learning to lift in a shirt or suit and in doing so, being capable of lifting more than you can raw.
With the belts, yeah, that's the way I would wear them if/when I use one. Loose and pushing my stomach against it. My opinion changed a little due to Dr Stuart McGills 'Ultimate Back Fitness and Performace' where he details that to feel the benefits of a belt, you actually need to be in flexion. So, you actually need to lift 'poorly' (as it was written).
Interestingly, just about every reputable coach whom I refer to for info references Dr McGill and that book in particular, speak very highly of him. They also recommend the use of belts for reps under 3. I would trust their judgment before I trusted my own. However, in the book it also says that there is no doubt that a belt increases torso stiffness, which increases load on the lower back, but still further ensures that the spine won't buckle during the lift, and this will add a few lbs to the lift, too.
One thing I noticed with my DL form is that when I first started doing it, I could lift with near perfect form for a 3RM. However, if I went for a 1RM or 2RM, my form would change quite a lot, hips would tuck and back would round (ideal time for a belt I guess!). I always change DL and Squat variations, one just for the variety and also to reflect where i'm weak in the lift. I do so with my assistance exercises as well. Recently I came back to DL's following knee injury, 2 months with no bilaterals, where I worked a lot on Glute medius and ironing out flexibility and strength discrepancies from side to side - which were subtle, really.
When I came back to DL's (about 3-4wks ago), I noticed straight away that my sticking point has changed. No longer is it 'off the floor' but around my knees now (woohoo, more rack pulls). I can also hit a 2RM with near perfect form, and my 1RM is about the same. There's rounding, but it appears to be from the upper back - so i'm told, but really need to get a video. So now I'm thinking - if it's possible that I can avoid flexion in the lumbar spine in 1RM lifts consistently, do I really need to use a belt?
And then i'm thinking, "that's all very well for someone who just wants to be strong, full stop. But I want to compete in PL, so... Get a dam belt"
I'm also thinking, 'if I use a belt for the 1RM, maybe i'll care less, lay it on the line a little more, and lift heavier'.
And then I think, "I drink too much coffee and type too fast for my own good"
In all honesty, If i were doing more singles right now I would use a belt... So i'm not against them completely, I just like to question things...