I did my CPL part time.
With delays, not having my mind properly on the flying when I came over after work, and conflicting priorities requiring me to cancel the odd lesson, it cost me a lot of time due to the slower learning curve of less intensive learning, which certainly cost me money. I'd guess doing it part time cost me around £3k.
Most of my other licences and ratings I did as intensively as possible, and certainly the more intensively I've done training, the closer I've been to minimum hours.
If I did something as big as that again, such as an IR, I'd do my best to do it full time. Time may or may not be an issue, but money certainly always is !
Bonus is good, although hampered inevitably by British weather on occasins. I've personally had poor experiences with David Coulson and wouldn't use him, but understand that many other people do like him and his teaching. I have always been very impressed with Wycombe Air Centre. So far as I know, WAC and Bonus both will teach you part time if you ask them to.
G