I ran my prison break last night.
The players were able to escape, and they took the way I thought was harder - they fought their way out through wave after wave of guards. They took on a level 7 encounter, even after the Pyromancer had already blown his daily during the initial escape. Nobody even dropped, though the Paladin came pretty close. He was handing out temporary hp like candy though, and his longtooth shifter regen was helping keep him up, as was resist all (wis mod) after spending a surge (from Virtuous Recovery).
The Thief was consistently doing 20-something damage per hit, which was nice; everyone commented on the Thief's damage output. Consistent, and high without being overpowered.
The Pyro-Mage was throwing some nice damage around as well with her cinder wand (she smuggled it in *somehow*

), and got several critical hits in, typically 15-20 +1d8 +1d10, so that really helped as well.
The best part was that because they busted out that way, I still have an evening's worth of adventure for the next time we need to do a one-shot. I was actually hoping they would take the sewers, but I guess that will be for next time.
One more thing that I did was because everyone was without equipment, so as not to make them fall too far behind "expectations," I gave out two boons to each of them.
The Thief had Torog's Lament of the Shackled and Davros' Defensive Step, the Mage had her smuggled wand and also Primal Blessing of Fire, while the Paladin had two item-equivalent boons - one worked like a Cincture of the Dragon Spirit, and the other worked like a Belt of the Brawler.
Overall, we had a pretty good time. It was my first time DMing 4th edition (though I am a 20-year veteran GM with 2e, 3.x, Shadowrun, CoC, and Palladium) and I have to say that I thought it went pretty smoothly. Combat went decently quick, though that was probably at least partly due to only having 3 players, but we got through two at-level fights and one level +3 in the span of an evening, with roleplaying, a skill-challenge to break out, and collecting some spoils of victory.
My next actual campaign that I'll be starting in a few weeks will hopefully go as smoothly, though there will be twice the number of players. Thanks for reading, and comments (et cetera) are welcome.