After I have slightly modified the FC6144 (open device and foam ripped out of the outlet openings, rubber closure flap away at intake), the output increased noticeably and was even better than the device in new condition.
Conclusion: Definitely useful suction for crumbs and lint removal on hard surfaces. If carpet or upholstery cleaning power is not recommended, as the dirt in the soft material often gets caught and the suction power is insufficient to pull away the dirt.
Battery performance is fine, 9 minutes, but not entirely without loss achieved (which I did not expect). But even when the battery is low lint and crumbs are absorbed (as I said, on hard surfaces!).
Disadvantage: Long charging time. 12-15h until the next job you should take into account.
My next model will probably again Philips, however, higher battery voltage (more suction power never hurts).