The Leo appears to be smaller than the N810 in every dimension. This makes it highly pocketable for me, as I could comfortably pocket my N810.

If the figures circulating on the web are correct, the Leo is 121 x 67 x 11 millimeters. The N810 is 128 x 72 x 14. The N900 is 111 x 60 x 18.

Comparative volumes (in cubic millimetres) are: Leo 89177, N810 129024, N900 119880. Of course, the Leo doesn't have a physical keyboard. Also, I assumed rectangular shape which is a simplification.

Regards,
Roger