Perhaps more than anything in photography, you get what you pay for with a tripod. The difference in build quality between a £50 and a £150 tripod for example is marked. I use a Manfrotto MN055 with a ball and socket head. I bought it from Teamwork about 12 years ago when my previous tripod (a Manfrotto Triaut) finally fell apart.
It fell apart because about a decade beforehand, it fell out of the cargo hold of a plane and hit the apron head first. This 20 foot drop onto tarmac meant it bent one of the arms of the head, chipped the paintwork and damaged the main casting... and it still worked for another ten years.
That's how solid these tripods are.
My MN055 is the previous version and I would like to update to the newer leg locks and a central column that turns into a side arm (like the newer models). Trouble is, if it ain't broke don't fix it, and unless this one falls out of a plane or gets run over by a steamroller, I can't see how it gets broken.
Mike uses a smaller, more modern Manfrotto 190PRO and the same built-like-an-Abrams logic applies. He's also shot on large format using dirty great Gitzos and Manfrottos designed to hold a 5x4 view camera in place. Trouble is, once you've used one of these things, it's hard to look at products like the Jessops tripod without thinking it looks a bit plasticky and lacks stability.
However, the big issue with any pro-grade tripod is weight (forget price for now... if you are lugging a heavy tripod up a hill, you don't say "my, this tripod's expensive"). The Jessops tripod weighs just over 1.5kg. The 190PRO weighs 1.8kg... and needs a tripod head that might add an extra kilo to the equation. This might not seem like a big deal, but consider these two opposing arguments:
1) Do you really want to lug that extra weight around whenever and wherever you need a tripod (and lug it back afterwards)?
2) If you put your expensive DSLR and lens on a tripod, do you really want one that's lighter than your camera from a centre-of-gravity perspective?
You need to weigh up which is the bigger 'no'...
If you are still undecided, here's a good test. Place a DSLR and lens on the tripod and extend the legs fully (leaving the centre column unextended). Lock everything down properly and place the tripod on a level surface. Now stick your finger on the camera's hot shoe and 'waggle'. If there's any movement at all, keep looking. A good tripod should also be able to reach about chest height with legs (but not centre column) extended... if you have to extend the centre column to reach more than 4' from the floor, keep looking.
Hope that helps