So you don't think there's a sweet middle road between super easy and super swingy?
Well sure, but I think that 4e is already pretty well there. Given that "there" is a range and not a specific spot, you can get all around in that range by varying the monster mix- an all-MM3 encounter will be noticeably tougher than an all-MM1 encounter, for instance. But the thing about the value of a healing surge is that it's already 25% of your maximum hit points, and most of the basic leader healing powers add some d6s on top of that. So, at least as far as my personal preference goes, if you make a surge worth more, the amount of healing you receive when a surge triggers becomes so high that it sort of trivializes damage.
Until the MM3 revisions to monster damage, I thought that 4e was a little too easy. The power of a healing surge was a direct contributing factor in the formation of that opinion.
It might be. I'm just trying to figure out exactly how the style of play would change.
I think combats get easier or you have to increase the monster damage to compensate if you want to keep the relative balance of damage to hit points between monsters and pcs. Increasing the damage-at-a-whack means swingier combats because a pc is more likely to go down from any given attack, as does increasing the value of a surge (you go from unconscious to not even bloodied with a healing word, pretty much automatically if the value of the surge is half your hit points, which means the healer doesn't ever heal anyone until they are well and good bloodied because it's wasteful).
If you leave everything else alone, combats get much easier; and all those "burn two surges" powers that leaders get (
cure serious wounds and so forth) become "almost dead to full hp" powers.
On the other hand, monsters that actually get to use their healing surges (MM1 orcs and vampires, for instance, or critters with "use a healing surge" magic items) will become significantly grindier without become much more exciting. This is because pretty much all of them are from early 4e, meaning that they don't do enough damage to be all that threatening; the newer monsters pretty much never burn surges.