I have both...the 17.5 mill is from Advanced Auto Parts? Yes?
I also have the Sams, and the Costco/ HF HID
I will say this...
Even though I LOVE my HF and my 17.5 mill AAP light....if I was just buying one I'd get the Sams in a heartbeat.
More throw than any practical person will need and a MUCH easyier packge to carry.
I just wish I could get a N30 from Amomdo tech but alas....
I got my "Big Orange" HID from HF first, and it does have the "shock and awe" factor even before it is turned on, its just so damn big. The 17.5 mill is almost the same size just slightly slimmer in the body with only one stand leg instead of two.
My advice if you want a "show off" light (and I did, no shame in admitting it) get the 17.5 mill, the sheer size alone will impress your freinds.
However, if you want a light that is usefull AND can be shown off spen the extra $22 dollars and get the Sams.
I learned that I HATE lugging the two big spotlights around.
Good Luck!
Oh yeah and +1 to everything mdocod said...thats what I get for posting after drinking....:drunk: