Need help deciding...SXPS16

okay, sorry for the trouble again lol
I have chosen this config from the Dell outlet, i was hoping if people would give me a few tips pros/cons about SXPS16 vs SXPS13 vs sony SR my budget is 1100 but no more than 1200 at all
here are my specs for the SXPS16

Here are the specifications on your system purchase:
Studio XPS 16 (1640) Laptop: Intel Core 2 Duo P8700 (3MB cache/2.53GHz/1066Mhz FSB) w/2.0MP Integrated Webcam
Qty :1
Price :$1,099.00 before taxes

System ID: 04MC6BJ3
CPU Speed:
CPU Type:
Mod Number: Mod Description:
M412C 125V Power Cord
HW426 90W AC Adapter
U338C 6 Cell Primary Battery
T013C Microsoft Works 9.0
U264H 64BIT Operating System DVD
W871N Windows Live
K811H 64BIT Operating System CD
N377N Studio XPS 16 (1640) Laptop: Intel Core 2 Duo P8700 (3MB cache/2.53GHz/1066Mhz FSB) w/2.0MP Integrated Webcam
P916C 4 GB DDR3 SDRAM 1066MHz (2 DIMMs)
P155D 500 GB SATA Hard Drive (5400 RPM)
H229H 8X DVD+/- RW(DVD/CD read/write) Slot Load Drive
R989D 512MB ATI Mobility RADEON HD 3670
G019C Intel WiFi Link 5300 802.11a/g/n Draft Mini Card
WU658 Shipping
P420X Shipping Material
R588G Label
T703D Notebook Keyboard
H432H Information
DR464 Operating System Label
U982D Resource DVD
M239M Software
J206C Dell Support 2.0 Software
P641P Creative Camera Software
DR624 Power DVD Software
M017R Power DVD Software
M434H Software
T180K Facial Recognition Software
U592C Service Software
T257H Roxio Creator 10.2 DE
J019D Software
Y720M Dell Support Center 64 Bit 2.0
XM544 Image Restore Software
Y425G Software
W108D 16 inch Edge-to-Edge FullHD Widescreen RGBLED LCD (1920x1080))
P166F Genuine Windows Vista Home Premium
K478H Obsidian Black with Leather Accent

STUDIO XPS 16 - M1640: 1 Yr Ltd Warranty, In-Home Service after Remote Diagnosis, 24x7 Phone Support (Included In Price)
Qty :1
Price :$0.00

my problem is, im not much of a 14" over person becuase i carry my laptop ALOT and the heaviness can be a burden...i was about to get the SXPS13 but the intel wifi issue seem to be bothering me.....so i decided to go for the SONY SR390 and its nice since it uses the same 512MB graphics card as the SXPS 16 does, my prob is i had bad experinces with SONY USA and on top of that refurbished and it only comes with 90 day warranty and that equals to a 1300 price point since the laptop itself is $1189
im really confused so i turn to you guys to help me out
i live in UK but having whatever laptop i get from USA
please dont tell me to check out the SXPS16 thread, i tried following the SXPS13 thread and i only got to page 46 after 3 weeks lol its too much trouble...so please help me out
oh and the SR and DDR2 mem...since this is gonna be a 2yr+ laptop i hope that wont be a problem
I want the SXPS13 but....ahhh i dont know please help..
P.S. i heard the SXPS13 speakers is really crummy....coming from SONY SZ...i hope its not going to be too much prob ...maybe i should just go with the SXPS16