Ill buy you some glasses to help with your blindness. It's nowhere near a 350D.
n00bwithmoobs owned you.
300R
350D
The case layout is similar considering the age, its just cosmetic changes;
TECH SPECS
350D
Warranty Two years
Dimension 17.7" x 8.3" x
17.3"
MB Support Micro ATX, Mini ITX
Expansion Slots 5
Form Factor Mid-tower
Material Brushed Aluminum and Steel
Drive Bays Two 2.5”, two 3.5”, and two 5.25” tool free drive bays.
Cooling Front 140mm and rear 120mm cooling fans. Room for up to five fans total.
Front I/O Dual USB 3.0 ports
Power Supply ATX (not included)
300R
Warranty Two years
Dimension
19.1” x 8.3” x 18.7”
MB Support ATX, mATX
Expansion Slots 7
Form Factor Mid-tower
Material Steel structure with molded ABS plastic accent pieces
Drive Bays (x3) 5.25", (x4) 3.5"/2.5" Drive Caddies
Cooling (x6) 120mm/140mm fan mounts, (x1) 120mm fan mounts, Includes (x1) front-mounted 140mm fan and (x1) rear 120mm fan
Front I/O (x2) USB 3.0, (x1) Headphone, (x1) MIC, Power, Reset
Power Supply ATX (not included)
Small subtle changes to form factor and incused by sizing changes. The 350D is longer marginally while the 300R is taller marginally as to the rest of the tech specs they are by and large the same so we move to cosmetics;
1) Brezzles, the 350D uses the Obsidian style front while the 300R uses the Carbide styled front brezzle.
2) Change in form factor changes the cable management routing and the addition of rubbering gromits are more to do with age rather than structual (300R is old)
3) The expansions are all by and large the same bar 2 plays 3 5.25" bays and the layout of 2.5" and 3.5" bays.
So the long and the short is that the 350D is very close to a 300R but double the cost for cosmetic updates.