Those are two totally non-comparable models.

The basic fact you need to consider first is that "i5" and "i7" processors right now come in two different varieties, dual-core and quad-core; the former are also "U" series (ultra low voltage) and the latter "H" series (regular low-voltage mobile processors.) So there is a big difference in the speed per core.

My own opinion, for what it's worth, is that on the dual-cure U-series processors, the i7 is almost never worth paying extra for. The i5-6300U or i5-6260U are pretty much the only processors to look at on machines with a U series processor (unless extremely price sensitive) -- if you need more performance, moving up to an H series i5 should be the next step, not a U series i7.

The T460p uses H-series quad core processors, and a T460p with an i5-6xxxHQ is going to be hugely faster than the Inspiron with an i7-6500u.

So, first, figure out which line-up of processors you need. If you need the quad-core H series, you will have trouble reaching your weight target; the lightest quad-core systems are around 4lb. The Lenovo T460p and the Dell E5470 (which confusingly sells with both H and U processors; under the skin it is two different machines) are the only two inexpensive(-ish) 14" business machines with H-series processors that I'm aware of, although HP may have snuck one out. There are plentiful lower-end gaming machines with those processors in the $1000-ish range, but the weight is going to blow hugely past your limit probably around the 6lb mark. There are some very nice 15" thin-and-light workstations from HP and Dell and a couple of consumer manufacturers with Macbook Pro clones (e.g. Dell XPS 15), but they're still around the 4-4.5lb mark and hugely past your budget (usually start around $1500)

In terms of the specific machines, I tend to only follow the business line machines, and have been a bit burned by Dell's consumer products in the past. The Inspiron is from their consumer lines -- it looks reasonably solid. Also, it appears to be a 2-in-1 which if you don't want a touch screen seems like an odd choice: http://www.dell.com/us/p/inspiron-13...in-1-laptop/pd (OTOH, they may have more than one "Inspiron 13 7000 series" -- there is a real 4-digit model number corresponding to the machine -- in that case Inspiron 7368 -- but their present branding hides it. I find thins annoying.)

Dodge DeBoulet's suggestion of the T460s is an excellent one if your budget permits and you want a U-series processor; the X1 Carbon (with several related submodels) would be a good one to look at as well although I'm not sure it's manageable in your budget.

The closest equivalent from the Dell side is the E7470, which is a superb business ultrabook. I'm not sure it's manageable in your budget, though, at least without going to refurbished models

The Dell XPS 13 might be worth looking at on the consumer side. XPS is Dell's "premium" line for consumer machines, and might hold up better than the Inspirons.

If you want a bigger (15.6") screen and can use the U-series ultrabook processors, there are quite a number of 15" ultrabooks around the 4lb mark, and some of them probably around your price range, but that is a sort of machine I have never followed closely enough to have any hope of giving a recommendation.

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Serious question: can you use a Mac? The Macbook Pro 15" is pretty much the lightest 15" full-power machine (with a quad core) and the rumor has a new, even smaller more compact 15" coming out soon (probably the far side of $2k in a good config, though!)