I live quite close to Telford Park and often walk/run/cycle through it. It's a lovely area, and you would definitely get more for your money than BTC. Many houses from the 1920s-30s, which are more spacious than the traditional Victorian ones, and bigger gardens.
You wouldn't have Northcote Road, but Streatham Hill has lots of shops and cafes, and you are still close to Balham.
Very close to Tooting Common.
You would have to consider how it would work for commuting time/school run depending on your children's age and on whether you would be looking at schools in the area - Streatham Hill has less frequent trains than Balham (let alone Clapham Junction), but Balham is quite close.
As you can guess, I am definitely in the "Telford Park" team - but I don't particularly like Northcote Road, so not living nearby is not a problem for me