It sounds like Sako has fixed it, or at least has a fix for the mag issue. Some have reported that when they've called and complained to Sako they replaced their magazines with what I assume is an updated version.
At $1000 it's worth the risk I suppose, esp. if it's just the mag issue because there are fixes for that. If you get one that doesn't shoot it's more problematic, because there are so many places blowing them out right now that used value is pretty horrendous and Beretta is horrible to deal with as a proxy. Even though my 300 was a lemon I've been tempted to try another one at that price and buy another barrel lottery ticket, but I think I'll just go to a Seekins, it's not much more $ and they seem to be very consistent accuracy wise. Solus is another option, you can get the action for around $750, even a nice prefit is say $700, that leaves plenty left over for a nice stock to stay under $2k.
I don't think the S20 did well in the states, Bass/Cabelas I know dropped the Sako line completely in the US. It's too heavy to be a competitive hunting rifle, scope mount options are not flexible, the stock is very slick/noisy/plastic/cheap feeling (even if it's not weak etc.), and many of the options for competition shooting (heavy barrel, 2 stage trigger) have never been offered in the US. The mags are a weak point obviously, they don't seem very well designed/executed/finished. It seems like Sako in general is struggling with hunting offerings. I think a lot of the big box/name companies are struggling. They can't be price competitive, with places like Seekins etc. offering really good shooting rigs for under $2k, who wants a browning, sako, etc. at over $2k? The only thing they really have going for them is volume and being in every storefront.
It does have a nice feeling bolt, nice machining, a very good single stage trigger. If they had a switch barrel setup, a solid feeling/textured stock offering, a 2 stage trigger etc. it could really be a winner. However we're also the 1-5% of shooters that likely can shoot descent in the first place and really don't matter to most manufacturers. Most from what I see at the range, can't push a 1MOA rifle to it's limits anyway, most of the hunters etc. I see show up that are most range are more than happy if they shoot 2-3" groups. 90% of the guys buying hunting rifles will never push their accuracy limits, so even if they produce some percentage of guns that are not up to a 1MOA guarantee they will get very few of them returned.
Sako clearly is cutting LOTS of corners on the s20. Lets look at pricing, you can look at something like the 90 Adventure, fiberglass stock but not full carbon (just some reinforcements evidently, nothing super special here, 7.5-8lbs for a 300 Win mag, but price tag $2700. Considering the S20 MSRP was only $1600 originally.....that's a lot of corner cutting. Even the new version of the S20 is like $1800. that's still almost $1000 less for basically the "same" feature set.