If I decide to buy a new Gen4 G17 what should I look for/upgrade?

[the_swede]

Is the grip on Gen 4 without backstraps significantly slimmer than the grip on a Gen 3?

[BWT]

Is the grip on Gen 4 without backstraps significantly slimmer than the grip on a Gen 3?

I would handle one. You can find them at almost all gun stores, Academy's, etc.

Normally an objective question of most firearms you need to get a second opinion on.

I'd go ahead and handle one locally and decide for yourself, to be honest about it.