I have tried doing dieting alone but it never worked: I could lose weight, but then would gain it back within a year. Combining diet and exercise completed the feedback loop. Eating like crap meant feeling like I was going to die when working out. Conversely, eating well meant performing well. This clicked for me.
I still agree with his point that it's one of the best ways to spend that extra time, but I think it's important to acknowledge it and plan for it. The commitment of a one hour workout is quite different than one that's twice as long because you have to deal with after-work traffic. There's also the matter of which 5 hours, as not all hours are equal in value.
(Next you buy a squat rack. Or skipping rope, or pull up bars, or olympic rings. If you feel you need to use your triceps, buy olympic rings and do dips on them.)
The cage itself is good for squats, rack pulls, shrugs, high-racked overhead press (as opposed to cleaned presses), and bench press, among others. The safety pins can be used for additional protection where the bar might put you at risk, especially in squats and bench press. Most cages will have a high bar suitable for chin-ups, if not one can generally be added. Similarly a dips attachment. An adjustable pulley gives you the added flexibility of a cable station allowing for pulls with resistance at different orientations (high, low, mid). With front racks, you can work outside the cage while still racking the bar onto it, much as you would with your bar stand. Bumper plates and a platform allow for Oly lifts, which are great for developing not just power but strength (you can do Oly lifts without these, but it's safer and easier on your equipment if you do have them).
You can also set up a rack for use with bands, chains, or both, to change and target your training. A rack generally offers anchor points for bands (chains just get draped over the bar): http://www.t-nation.com/free_online_article/sports_body_trai...
Something like this offers most of what I'm talking about, many other cages do as well: http://www.texasstrengthsystems.com/powerracks.html
An adjustable DB is just a bar, a set of plates, and a locking ring that you can set up for a wide range of weights, it's cheaper than buying a full set of DBs over the same range, and the manual ones will give more range than the adjustable DBs you can typically buy (usually 5-50# or so, not enough for the serious lifter).
A rope hanging from the ceiling for climbing is pretty minimal equipment. Kettelbells (even just 2-4 of a few weights) offer some increased variety to a workout, though most KB moves can be done with DBs.
A Concept2 erg is something I happen to like, and if I had my own gym it's what I'd want.
Total space budget isn't all that huge
Powerlifting tends to make for longer workouts because I would take more rest between sets. When I would do BB or cut workouts I would be in the gym ~30 minutes. Keep in mind that this 30 minutes was full on balls to the wall intensity. It's the intensity that matters and not the time. Also, many people do not know true intensity. I know I didn't learn it until I started doing BJJ training and puking multiple times during 1.5 hour sessions. Protecting yourself and competition has a way of drawing people out to the very edge of what they are capable of.
There was an article recently in Outdoor magazine where even amateur marathon runners are training differently. Instead of slogging out many many miles, they have cut miles and are doing less work but at maximum intensity.
My goals were 500/400/300 DL/Squat/Bench, but I could never get the squat. My legs are long and I do true ATG squats. My quarter and half squats were into the 400s though. My other problem with squats was that I tore my ACL wakeboarding and have had it surgically repaired. It feels great now, but the timing set me back on my squatting.
Benching in the 300s hurt my elbows too much so once I hit that number I backed way off. I rarely bench over 250# during a workout now.
Most people would be surprised at "how little" bodybuilders work out. Sure, they work out much more compared to the average person, but less than let's say your olympic swimmer, volleyball player, etc
It's still a "full time job" but training is not a lot of time compared to other activities (mainly eating)
A power lifter might spend 3-5 hours a week, but a bodybuilder likely spends up to ten or more.