for $140 delivered this (little bear p8) is a bargain. but you are right, there is a potential for some issues.
1. this ships as a flat-pack so the final assembly rests with you. & depending upon whether you choose top-side component or bottom-side component pcb, power routing will change. hence, this explains why there is a male/female socket between the ac main housing (iec) & the xfmr. i.e. end-user will not be required to do soldering.
2. the iec assembly IS fused.
3. the xfmr assembly bolts to the acrylic (clear or red). if you accidentally overtighten (like I did) you will crack the acrylic .... in which case you reach for the bondic or superglue.
4. there are 4 output caps, all 'lytics --- at the least, these should be bypassed.
5. the 4 red wimas are indeed 0.1uf/630v coupling caps --- these too, should be bypassed, if not outright replaced.
6. amongst my friends & I, (with at least 4 pcbs) we have not experienced any egregious channel matching issues ---> you do need closely section-matched tubes, though.
7. to my knowledge current pcbs do not use those gold-colored metal power resistors --- instead, they are green-colored carbon resistors of considerable size.
8. I have used mine for up to 8hr continuously while running burn-in tests w/o issue.
9. the stock tubes, esp the driver tubes should be replaced --- i'm using ge jan 5670w. for output, i suggest rca 6as7g for those on budget, otherwise gec 6as7g.
10. I agree ... emi/rfi may be an issue ... but I haven't experienced it ... ymmv.
11. the open chassis is both boon & curse: boon for those into modding & curse, because the 'chassis' is rather flimsy.
12. I experienced two issues with my 'kit', both of which were rectified by the seller. the acrylic panel around the iec mousing was cracked and some of the standoffs were not threaded sufficiently deep to accept the interfacing standoff. if you're into modding, you will need longer standoffs in order to accommodate large caps - these are readily available on the 'bay.
hth,
even w/o modding i would be hard-pressed to find an alternative otl valve amp for less that sounds as good.