I can give 1 example - when I switch my Pure Scribe/SW mage from PvM mode, to PvP Parry mode.
When I switch from PvP mode to |PvM mode, I'm usually trying to do it in as fast as time as possible, say 1 minute.
PvM mode is all about SDI, Intelligence and Mana. I'm hitting 210 Mana, and wish to minimise Dex at 10.
PvP Mode - I put on my Damage Eaters suit, Reactive Paralyse, take off my 140 SDI, put on Parry. As part of the putting on Parry, I need to switch my Stats from 150STR/150INT/10DEX PvM mode to 150STR/120INT/90DEX PvP mode roughly speaking to make Parry work.
It's actually so hard to do, I stopped doing it, and instead when I go to PvP mode, I don't add Parry, but leave Spellweaving on.
You could all say, build another identical mage for different purposes, but my other character slots are full, and this is my main that I play in all game content.
I'm not sure if the example is strong enough to consider Stat Stones, you'd need to think about it. But it does affect my play, and limit my options. Another solution to my dilemma would be appreciated also.