I went back & forth over this same issue myself. I think it boils down to a couple of issues:
- wheelbase: Excursion wheelbase is 137", same as a Regular Cab Long Bed, or Crew Cab with 5' extra short bed (if such a thing existed, the short bed is actually 6.5'). The X is already a fairly big beast to maneuver in tight urban parking lots. Sometimes I can barely get in to certain parking spots in my X, and sometimes I can't at all (even reversing in which is often easier). Attempting the same with a CCLB, a full 3' longer would in some cases be impossible. How much of an issue this is for you depends on whether you have a 2nd car, or live out in the country vs. in a built-up urban area. But IMO, the X makes a pretty good daily driver
- cleanliness of payload / whether you care what the inside of your X looks like: a pickup has a separate bed, which has certain advantages if the payload you carry is often dirty e.g. car parts, hay (which would get everywhere inside the vehicle), etc. If everything you intend to carry will be clean, or can be packed inside boxes that are clean on the outside, then this is not such a big issue, and the X has certain advantages of having a naturally enclosed bed.
- max dimensions of potential payloads: this can be gotten around using e.g. a trailer, but if what you are carrying is regularly taller than the roof of the X e.g. a motorbike, or what you are carrying is regularly longer than 5' (assuming you want to keep 2nd row seating) e.g. 8' sheets of plywood, then having an X with only a 5' effective bed is going to be a hassle
I also wanted a Ford 7.3L PSD, and looked casually (I have a 2nd car) for about 6 months to a year, unsure of whether I wanted a truck or an X. I finally spotted a particular '00 X, and knew as soon as I saw it that it was what I had been looking for - it was in reasonable condition with a few niggles that needed fixing but nothing major, reasonably priced, reasonable miles, and all of the offroad mods that I wanted had already been done (i.e. 8" all spring i.e. no blocks lift, double resi shocks in front, single smooth bodies in rear, with rear airbag assist with small compressor & in-cab controls, 37" tires, 4.56 gears, manual locking Warn hubs, ARB lockers front & rear, Warn 15k winch stealth mounted behind regular bumper, Class V hitch, roof rack with 37" spare wheel mounted, drop down steps, etc.) and I bought it within 24 hours of seeing it advertised.
Anyway, the X has worked out well for me. After fixing the few niggles (driver's window regulator, power door locks, A/C condenser & receiver/drier & 2 shocks rebuilt as they were leaking from the seals), it's been relatively trouble-free (only needed one unit hub assembly, and an alternator so far, though I also upgraded both batteries when troubleshooting). I have also recently noticed that the rear airbags have now started to lose air, but the airbags are dry-rotted (over 10 years old), so that should be fixed pretty easily once I order the right replacement airbags (and the truck will work perfectly fine without them for the week or two that they are out. The X is actually just small enough to work reasonably well as a daily driver (I now share miles between the X & my 2nd car roughly equally, just depends on what I'm up to & what I feel like), and I enjoy driving it (especially as I also put a fairly decent sound system in it, with XM radio & iPod hookups). I sometimes use it to carry spare car parts or tools etc. to help out at offroad races, and so far, with using tarps and/or spares boxes, there are only a couple of extra scrapes & oily marks on the inside in the back (some of which would probably come off with a good scrub), but I'm okay with that - that is one of its main roles, which I knew ahead of time going in. The X does quite a lot of things well, it's my Baja / snowboarding 'mission' vehicle, offroad vehicle, tow vehicle, race support vehicle & sometimes daily diver, and sometimes fills multiple of those roles simultaneously e.g. towing a race car on a trailer to an offroad race, laden with spare parts & tools. I have no regrets buying it, and would do the same again, though I occasionally get a hankering for picking up a CC LB, just for the extra room (which I may still do at some point, in addition to the X, as the prices for the 7.3s have started to come down now that they're getting on in age). But really, the X is a much more practical daily driver. While I try not to do too many very short trips in it, it's a much more feasible proposition to pop to a local shop or corner store in the X than it would be to find parking in a CC LB, so I know if I got a CC LB, it would get used much less than I use my X, and so would be difficult to justify keeping around just for those special occasions when the extra room would be much appreciated.
The other truck I like is the 06 - early 07 MegaCab with 5.9L Cummins diesel. It's solid front axle, just late enough that it's available in MegaCab form i.e. decent cab size, instead of the extended or quad cab earlier versions, and issues with predecessors have been fixed, and just early enough that it isn't saddled with overly burdensome emissions restrictions. But having another 7.3L PSD truck would have some advantages over a Cummins i.e. only 1 set of mechanics to learn & the box of spare parts that I have stored in a crate could be shared between the 2 & swapped back & forwards depending on whether I was using the truck or the X. But I don't really need anything bigger than the X, and on the rare occasion that I do I could rent or borrow a trailer or bigger truck.
An E series has certain volume advantages, e.g. you can fit 3 motorbikes inside, but the engine has certain packaging disadvantages (it's pretty tight in there, and no room for intercooler, so power is derated vs. the X & SuperDuty trucks), it isn't available stock with 4x4 (though expensive Sportsmobile or Quigley, or home-brew solutions are available/possible). Also, the regular bed (RB) seems a bit on the small side for me, and the extended bed (EB) has a rather large rear overhang. Unless I needed the interior volume e.g. for expedition vehicle interior setup, or for storing motorbikes completely inside, I'd opt for an X, or a truck with either utility bed with lots of lockable compartments or a full bed length camper shell.
