First of all, doing Nitnem in 27-30 minutes and Siri Sukhmani Sahib in 40-45 minutes is not too fast. There are Gursikhs who normally do Paath in half the speed you mentioned and some may be even faster. As mentioned before, Bhai Atma Singh jee Panjokhra Sahib used to get up around 1:30 am or so and as soon as he used to wake up, Siri Sukhmani Sahib used to start within him, like a tape recorder and in 16 minutes his Siri Sukhmani Sahib used to get completed and this was even before doing Ishnaan. How many Paaths he did throughout the day, is beyond our imagination.
Doing Paath with love does not mean that you have to do Paath slowly. Love can be present there in both fast and slow Paaths and same holds true for Vichaar. As one's Surthee gets Balvaan (strong), one can comprehend and contemplate on Gurbani Paath, even when it's done fast. As the matter of fact, with Balvaan Surthee alone, one can do Paath at the speed mentioned above in Bhai Atma Singh jee's case.
The moral of the Vichaar is that one should do Paath in such way that one can derive Anand and Vichaar from it. It does not matter if it is slow or fast; love, vichaar and Anand should be present. Gurbani Paath, when done correctly, immediately initiates automatic and effortless Naam Abhyaas within.