Dell Inspiron 15 vs 15r

Is it worth paying roughly $100 more to buy a 15R over a 15? The specs between the two models I'm looking at are roughly the same, difference being the 15 is based on the 75HM Express chipset whereas the 15R is based on the HM77. The 15 only has 3 USB 2.0 ports whereas the 15R has 4 USB 3.0 ports. The models I'm looking at both have i5-3210M CPUs and I plan on upgrading the memory and HDD myself regardless which one I get. I don't have any USB 3.0 devices so I'm living in ignorance with regards to how fast they are. I do plan to take it with me from place to place and I don't mind the weight of either. Is the 15R any more sturdier than the 15?

That said, is it worth paying an extra $100 for the 15R?

 

Technically both are Inspiron 15, but the 15R has higher end options compared to the base Inspiron 15. No the build quality isn't much better, both are plastic chassis.

 

hmmm... I'm tempted to get both to compare for myself. My 15R arrived the other day. The i5 3210m is way more capable than I thought it would be. Stacraft 2, Diablo 3 and The Walking Dead all run pretty smoothly at low settings running at native res.

Starcraft 2: Played 1v1 AI PvZ on a couple maps. The fps never seemed to dip below 50fps
Diablo 3: Played until I found Cain and brought him back to town. The fps never seemed to dip below 25. Not sure as I didn't have the fps counter up.
The Walking Dead: Not sure about the fps, but it seemed to not go any lower than 25fps.