A properly fitted M70 style safety should not be unduly difficult to engage to the safe position. They generally do require a bit more effort to go from fire to safe than from safe to fire because it is compressing the mainspring as was stated. The M70 style safety is not unique in withdrawing the striker and compressing the mainspring however. Many rifles have safety mechanisms that withdraw the cocking piece and striker against mainspring tension. As originally designed (read: not Timney replacements with safeties) M98s, Springfields, 1917/P14, Remington 30 Express, and yes, even the maligned Remington 700 safety withdraws the striker against mainspring tension. The key is proper fitting of the safety and cocking piece so that the camming effect is smooth and properly uses leverage to withdraw the striker.
Ontario Hunter, your Parkwest 3 position should definitely be lifting your striker off the sear on a M98. In fact if it isn't it is dangerous. Most likely it is lifting it a small amount that is imperceptible. I personally like to be able to visually see the striker retract when setting up a safety. I fitted a Parkwest Safety to my .458 M98, and it definitely withdraws the striker as it should. If a M70 style (Parkwest) safety is not fit properly to withdraw the striker, the rifle can fire when moving the safety to fire without touching the trigger if the trigger was previously pulled. To adjust this a small amount of material needs to be removed from the cocking piece or the sear, so that the safety is withdrawing the cocking piece away from the sear.