i have a diverite for about 8yrs?
can't say it's 'the best' on the balance of numerous factors as others have alluded to.
looking back would i have bought it again? maybe not. then again, not sure what alternative brand i would buy either. maybe Agir Brokk from Sweden to match my Swedish Poseiden regs. If Singapore buys subs from Sweden it's good enuff for me.
some newer brands 'unproven' and seems like they focus on low price to get you buying that's it.
others from time to time have issues - perhaps no big deal as this is one in million type (eg. halcyon on the inflator springs) and also, some brands offshoot and make bcds when they aren't a bcd maker (eg. apeks, though it's awesome regs reputation so by right they should have good bcds). so troll around a bit, if u can test out friend's ask instructor if can help/give discount/lobang etc.
diverite single tank wing:
a) What's Great - simple, proven brand /long time in market, can combo purchase their online platform, straightforward, works well. no hassle. nothing broken, never replaced anything.
b) What's Not So Great - mine's old model, material a bit roughy than others (picks up slimy stuff when u brush against rock & other things), too many d-rings & stuff - non 'hogarthian' so purists find this an issue., plastic buckles in places such as crotch strap..square shape as newer oval ones claim more hydrodynamic etc. dump valve face outward (new designs face inward - in prone it must face down otherwise during failure your bcd would leak catastrophically esp problematic if u dealing with forced deco), some want left side dump always so right side always free esp air share donation - tech approach). there's an integ dump valve on shoulder of the bcd hose joint which is bad idea and a fail point.
also i mod mine in various things (shorten corrugated hose, take out useless items), and, replaced padded backpad with alum plate cos i didn't dive doubles anymore..doubles wing is Agir - awesome brand and they do have single wings.
Perhaps as a guide you can consider some factors:
Price - not always the key
Quality construction - often they say some kevlar sh@t but who the h&ll is going to shoot u i dunno.
Replacement parts - usually springs, and inflator button are universal, test these see if u like them
Warranty - local or int'l
Shape factor & fit to your body - your heigh typically is a big factor where it sits on you
Lift - usually a typical range, more if u got nice big nat geo camera
Hose length, position of dump valves - there's standard lengths depending what u like
Stainless steel type (i think there are two types of marine grade, one cheaper one higher) as it affects corrosion resist.
Cool factor - nice big halcyon label does impress, and colours too. lesser known may help strike conversatn.
Attachment stuff (points and how it integrates with future diving, backplate etc)
If want to buy wing and bplate/strap/rings separately. Bplate choice also another story on its own with factors to consider...