if I'm paying £100-150 I'd like to get it right]
Thats how I saw my choice as well - I've been needed a decent tent for years, and money is tight, so its something you have to think about. The Vango seems a perfectly fine tent, if thats what you want, and getting it at a good price is even better. However, there is always a tradeoff, and its up to you to decide what you want. You've had 4 or 5 other suggestions on this one thread, and its not going to get easier!
Best thing to do is to have a look at whats out there, what your budget realistically is, and what you want to use it for. If your going to basically car camp, then something big, relatively cheap and sturdy is fine. If your thinking of wild camping/walking/etc, then weights far more of an issue. The maxim is you can have it cheap. you can have it light and you can have it effective/durable - pick any two. Thats doesn't mean you can't get a real bargain (The Tiger Paw tent from Argos had a big fan club a couple of years back, and its was about £50), but its best to think what works for you. And getting inside a tent, even in a show room, can really help.
You have a big advantage - time. You can gather data, listen to others, and you can keep an eye out for real bargains. Ebay outlets, the Bargains thread on OM/classifed sales and flash sales from Cotswold, etc can all help you to buy better than you would normally be able to afford. You might get something decent 2nd hand, from someone who trading up or going lighter (in which case, buy Kristin Hostetter's Dont Forget the Duct Tape or the newer Complete Guide -
http://www.amazon.co.uk/Backpacker-...IES_1_3?s=books&ie=UTF8&qid=1424388680&sr=1-3 - £3.75 plus postage is excellent value - and might have you a lot of money).
One you know the field, its much easier to get whats right for you, and at a good price. Good luck.