The unified cartridge, where the heater and tip are one assembly (as seen in the TS100/Pinecil, T12, etc) tends to have much tighter thermal regulation than the separate tip style (T18 / 900M / etc). I've found it more than adequate on all but the skinniest tips.
Mechanically, eh, the grip-to-tip distance is already pretty long, another 3mm isn't going to change anything there.
The unified cartridge, where the heater and tip are one assembly (as seen in the TS100/Pinecil, T12, etc) tends to have much tighter thermal regulation than the separate tip style (T18 / 900M / etc). I've found it more than adequate on all but the skinniest tips.
Mechanically, eh, the grip-to-tip distance is already pretty long, another 3mm isn't going to change anything there.