Krogan have a shorter dash/evade range than humans which have a shorter dash range than Asari.
So yes, they are more sluggish in terms of agility (no wonder).
Also a character (e.g. Krogan vanguard or mercenary) with active Fortify has considerable reduced movement and sprint speed.
If activated they are 35% slower.
They are fat and often get in the way, as for kill stealing? ... I don´t care much about points in gold, all I care about is getting the job done as efficiently as possible, if some fat Krogan keeps killstealing me ... good on him/her.
But they are fat ... fill doorways ... and for that reason they can be quite obnoxious.
