Eureka spitfire solo V spitfire solo SUL

Mountain Designs is having a 30% off sale this weekend and I've been meaning to buy a good (as per the reviews) and cheap one man tent for a while now and for $105 & $161 (SUL) I can't go too wrong. Putting aside price and looking at both tents on it's merits the SUL tent is 500g lighter and does not have a pole at the feet, but in terms of performance you have the standard solo spitfire materials
•Fly: 75D Armatech Taffeta polyester, min. 2000mm PU coating, fire-retardant
•Inner tent: 40D Nylon no-see-um mesh, fire-retardant
•Floor: 75 D Armatech Taffeta polyester, min. 3000mm PU coating, fire-retardant
•Poles: 8.5mm. T7001 Aluminium
http://www.eurekaeurope.com/p/spitfire-solo/tents_lightweight?pp=136
Vs for the SUL
•Fly: 20D Both sides siliconized Ripstop Nylon min. 3000mm
•Inner tent: 20D Nylon R/S B/R
•Floor: 40D Ripstop nylon, min. 10.000mm TPU lamination, fire-retardant
•Poles: 8.84 mm DAC Featherlite NSL aluminium poles
http://www.eurekaeurope.com/p/spitfire-solo-sul
The standard tent seems to use more durable and I assume waterproof materials. but in practical terms what does it actually mean i.e 40D v 75D likely to rip, let water through in a storm etc and is the trade off in weight too great?
any experience or knowledge would be appreciated.
cheers,
•Fly: 75D Armatech Taffeta polyester, min. 2000mm PU coating, fire-retardant
•Inner tent: 40D Nylon no-see-um mesh, fire-retardant
•Floor: 75 D Armatech Taffeta polyester, min. 3000mm PU coating, fire-retardant
•Poles: 8.5mm. T7001 Aluminium
http://www.eurekaeurope.com/p/spitfire-solo/tents_lightweight?pp=136
Vs for the SUL
•Fly: 20D Both sides siliconized Ripstop Nylon min. 3000mm
•Inner tent: 20D Nylon R/S B/R
•Floor: 40D Ripstop nylon, min. 10.000mm TPU lamination, fire-retardant
•Poles: 8.84 mm DAC Featherlite NSL aluminium poles
http://www.eurekaeurope.com/p/spitfire-solo-sul
The standard tent seems to use more durable and I assume waterproof materials. but in practical terms what does it actually mean i.e 40D v 75D likely to rip, let water through in a storm etc and is the trade off in weight too great?
any experience or knowledge would be appreciated.
cheers,