I toyed with the idea briefly, but space was just to big a factor for me. 1/72 has a fantastic variety of models available, and there are some really great looking pre-painted kits out there too. My Dad has a collection of 1/72 scale planes that goes from the Wright Flyer on up to modern day Stealth fighters. It's about 800 in all, and it is absolutely amazing. It's been in the making for over the last 40 years. If there is a kit in 1/72 scale, he has one or more. He has about 200 armored fighting vehicles from early on, up to modern, and a small 1/72 scale fleet of about 10-12 PT & E-Boat sized boats, with the crown jewel being a 1/72 scale German U-Boat! Several landing craft boats as well, of various sizes. I can't remeber if the B-52 or the B-36 is the biggest, although some of the modern Soviet bombers are pretty big too.
1/144 scale are easier to cranck out, production style for me, as I'm going for 3 each on the bombers, pairs on the fighters, and singles on planes like the Japanese Emily & Mavis, and the US PBY Catalina. I have 188 kits on hand already, with about 125-130 completed and ready for play. About 50 or so I still need to build, 10 being shipped to me. You can play at this scale on a decent sized kitchen table. Plus, they are much easier to transport and store. I do my 1/144 scale planes in "wheels down" fashion, which makes them easier to display or look at, but in "wheels up" mode, there is less to risk being broken, and they look super on the stands!
Amazingly though, I think the cost factor for 1/72 scale doesn't seem to be too much more than 1/144 scale! At least from what I've been seeing in the local hobby shops and on E-Bay. If you get into some of the bombers though, you're going to pay more in 72 scale. I grabbed 3 x B-17Gs in 1/144 scale for $5.95 apiece, pre built and pre-painted, they look fantastic. I got 3 x B-17Fs for the same price. That's going to be hard to match in 72 scale. I have 1 x B-17C/D, 1 x B-17F and 1 x B-17G in 72 scale (all unbuilt), and I paid on average about $19-$20 USD for them in local hobby shops, some time ago. I'm off work tomorrow, and I'll be going down to my favorite local hobby shop tomorrow to get some paints; I'll check out the local market for prices. I know I've seen the 72 scale pre-assembled, pre-painted fighters at around $10 USD in both hobby shops, and in toy stores here in C-Bus, OH. 21st Century has some super ones, as well as some other toy company, that I can't recall off the top of my head right at the moment.
I've got a few 1/72 scale kits still around that I have't "loaned" to my boys, and about 45 or so unbuilt still; I may have to keep tabs on this thread...