Can you let us know about some other parameters?
Are you looking for 7x, 8x, or 10x? More compact (e.g. 32mm) or full sized (42mm)? Since you've owned other pairs, what are your priorities, e.g. brightness, size of sweet spot, sharpness, overall field of view, fast focusing vs. slower, etc?
At the "budget" level of 300 USD there are many fine options but each will inherently make their own set of compromises. For example, the popular Nikon Monarch and Eagle Optics Ranger are quite rugged, light and compact for 42mm models, with good brightness and sharp center optics, but have fairly narrow fields of view compared to the competition and don't do well with controlling color fringing (chromatic aberration) compared to some of the recent "China ED" models.
Since you are in London, I would assume you have many options for shops where you can go in and try some models out. The best thing to do is find a pair that "fits" you, so you can decide what you like/dislike and figure out what compromises work best for you.