The one i bought is to secure http://store.treocentral.com/content...-24--155-2.htm Its not realy difficult to put the phone in the holster as long as its lined up and you push it in smoothly and alittle quickly. It is however difficult taking it out, you have to press very firmly with 2 fingers on the bottom of the holster to remove it. I dont have any experiance with the seidio for the treo 600. I do have experiance with the proclip for the 600 and its perfect. The proclip for the 650 is now available http://www.proclipusa.com/?sectionpa...oryid=&p_year= . Sorry to keep posting the same links but it would be easy to confuse all the different holsters.