I used to be an avid Amsoil user but its fallen out of favor with me in recent years.
Here's why:
Around 2010, the EaO oil filter was redesigned. It went from 98.7% @ 15 microns to 98.7% @ 20 microns. During this time I discovered the EaO went from WIX/Donaldson construction to Champion Labs construction. Others made the same observation ->
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2551795
When I asked Amsoil why an EaO costs $14.30 plus shipping and tax when the identical filter can be purchased from Amazon for $11.31 Prime? They flat out told me it's the dealer structure that inflates cost. Not making it up. Still have the e-mail. At that point I stopped buying EaO oil filters.
Then there is the Amsoil EaA Air Filters. I used to use those in the one vehicle they had an application for, but now they are discontinued.
The motor oil, after trying all three product lines in my applications, OE/XL/SS, I don't find it particularity the best bang for the buck. The SS did fine in my Van but I only drive about 5k miles per year, so I don't feel I can fully take advantage of the added cost. Then the OE and XL products don't really have anything to offer over what a name brand full synthetic can offer. In recent years the competition has really firmed up, this particularity with SOPUS GTL motor oils IMO.
For example, say the average consumer wants to buy only five quarts to do an oil change, typical. The price per quart including sales tax, shipping, PC fee versus the SOPUS full synthetic they can buy from the big box store:
Product---------------------------------------PP-------SS--------XL------------OE----------QSUD
Noack Volatility (ASTM D5800)----------------- 9.10------7.6------10.5----------10.9-----------8.8
CCS Viscosity (ASTM D5293)-------------------4080------3398-----5524----------4945---------4184
Total Base Number (ASTM D2896)---------------9.02------12.8-----9.0------------8.1----------8.5
Viscosity Index (ASTM D2270)-----------------171-------171------160------------166----------172
API SN---------------------------------------Yes--------Yes------Yes------------Yes---------Yes
ILSAC GF-5-----------------------------------Yes--------Yes------Yes------------Yes---------Yes
ACEA A1/B1-----------------------------------Yes--------Yes------Yes-------------No---------No
ACEA A5/B5-----------------------------------Yes--------Yes-------No-------------No---------No
GM dexos1------------------------------------Yes--------Yes-------Yes------------Yes--------Yes
Acura/Honda HTO-06---------------------------Yes--------No---------No------------No---------Yes
Price Per Qt. incl. Cost/Tax/Shipping--------------$5.42-----12.27----$10.06--------$8.39---------4.73
Not bashing Amsoil, I still use some of their products. IMHO, as far as I can tell, their gear lubes, trans fluids, power-sports and outboard products are a good value. For the average over-the-road motorist, the motor oil and oil filters are dated.