I will always take Quick and Dirty, and then say "but...".
I've seen countless Living Spycraft tables where the gearing up phase really dragged. With new players, it is brutal. An experienced player pretty much has to walk that new player through picking gear and help make the picks for them (brutal in the original 2.0 printing), all while somehow making their own. I can say that while it was intriguing, it didn't sell the game well. Throw in more than one new player and the feedback was usually "I had a blast, except for picking gear".
As a frequent player of a Wheelman, I enjoyed creating a custom spreadsheet by caliber and type of mission/terrain covering the more likely picks I would make, including all modifications. It took hours of work to create that spreadsheet so I could make the decision in 30 seconds during actual play at the table.
So, I really think Quick and Dirty is best for the game. But, I don't see why the foundation of quick and dirty picks can't allow for an option to do more work. It's a bit like this:
Option A: Choose a gun from these three. The gun is a good gun.
Option B: Choose any "unmodified" gun, which is weaker than the one in Option A, then add x gadgets/upgrades/components and you end up with a good gun.
We can take it further, where Option A is really: Select one of these three bundles, then add one item from this list and optionally swap any item on the bundle for one of these 3 mission-specific picks. Option B is to design your own bundle with all the work of customizing/etc.
A different model, which I probably like better, is where your personal gear would be customizable and your mission gear would be a quick pick bundle. It might look like this:
1) Every PC has some personal gear. You might do the original two choices above (A, take a modified quick pick that is good; B, take an unmodified pick and modify it until it is good). This works well, because you can either whip up a quick PC and play or you can spend tons of fun time at home customizing your personal gear for your style. Everyone wins.
2) During the mission's gearing up phase, you are given bundles. It's the agency resupply van that pulls up, it's what Q has in his headquarters, it's your group's secret cache, etc. The bundles are quick pic, with maybe the option to swap an item or two, but no customization. We want this to be super-fast, mission-specific, and part of the fun is picking at the table.
Aside: I'm an admin for the D&D 4E Ashes of Athas organized play campaign. In this campaign (set in the Dark Sun setting) all PCs are part of the Veiled Alliance (undercover mages, wanted by the government). We used a refreshing "kit" of equipment to lessen the issue of tracking gear. But, in retrospect, I wish we had gone with a bundle pick at the start of every mission. I think the adventures could have been cool if you had to choose between extra water and rope, between sun protection and extra ammo, between the 10' pole and the grappling hook. (And, of course, the adventures would reflect those choices, making such equipment valuable in different scenes).