I completed the ATPL course at Stapleford within the past few years.
The instructors were excellent and the evidence was visible in the class results, with multiple students averaging >95%.
They're also partnered with an EASA ATO so that they can offer both UK and EASA ATPLs, so you can dual license if you want.
Personally, I would highly recommend them. I also went on to do my CPL / MEIR there and would also recommend those courses.