Who really knows seo???

Age matters a lot, as do other on site factors... your content, optimisation etc.
Link Variety / diversity matters.

PR is an indicator of the strength of a link, but nothing more... hi PR does not necessarily mean it is a better link, particularly in HPBL networks where there are 50 sites each with a piece of spun crap on the front page with the same 70 links as every other site in the network.

As for your PR4 vs PR6 question, it all depends on the site, and how it got that PR. If the PR6 is a bad site spammed up to the eyeballs, and the PR4 a genuine quality site with legit links... then the PR4 may be better... but, PR is on a kind of logorithmic scale, a PR6 is MANY times stronger than a PR4... so generally speaking, the PR6 would be the better link.

TBH... I think this question is a waste of time unless you actually have to choose between the links... which is unlikely... as if you could you would take both links wouldnt you?

My point is you have to work with what youve got... take whatever you can, leave nothing on the table... that is my approach :p

Toolbar PR is a lagging indicator and measures the quality of links but does not tell you how "strong" a site is. The doesn't tell you what "today's" PR is either. Only the backlink profile will tell you this. A PR5 with 100 PR6 backlinks will pass more juice than a PR5 with 1 PR6. OBL plays a major role as some HPBL networks have an OBL of 150 (!?!), while quality networks restrict it to 70.

I don't agree that unique content determines the quality of a HPBL. It just helps the HPBL from being deindexed (obvious footprint), some of the best HPBL I've seen have nothing but scrapped content thats poorly spun yet do wonders for serps.

My reccomendation is simple, stop looking at your competitors and start getting links of your own. I use to do the same thing as you did, but now all I do is focus on building my own network while networking with others to find other networks to be a part off and its paid off big time.

The basic premise to building links it to start with great unique content on your site, then place the contextual links to relevant pages and site and build gradually over a period time with a new site. Do not buy a 10K link package, this will give you a penalty possibly.

I was trying to make is that my competition sometimes only has about 100 backlinks all diverse but the hpbls he has are pr 0 to pr 3 I have over 8000 all diverse again and I have pr0 to pr7s pointing towards my site I don't really watch my competition to much but it's hard not to when I don't understand how they are ranking higher than me when I have better quality bls maybe it could all to do with the age.

Domain age is not the only factor to ranking higher. And you are comparing only BackLinks of your competitor's sites. There is also there things to compare and you may know them very well.

Good HPBL networks certainly work well, as all contextual backlinks do.
The problem is to find a good HPBL link network. I have tried a few of these but until now ive seen only crap sites ( in terms of link value).

Most will not reveal their urls, even after entering the network, so you have monitor the gained backlinks yourself, usually to find out they are a bunch of CRAP.

PR is only a small indicator of link value/authority of a website. In the HPBL networks where i got some links there were several high PR7 & PR6 sites, but their seo value close to 0 :-(
A much better indicator of a valuable page to get your links on is Page/domain authority ( free toolbar from seomoz) Im not a fan of Rand Fishkin at all, but his toolbar works. the domain and page authority toolbar does give a good indication if a site is valuable or not. This info combined with the pages PR and "page rating" from ahrefs tells you a LOT more about the value of a site. Ofcourse there are other factors ( like unique - non spinned content, number of outbound links ect.)

From my experience HPBL networks are CRAP

However, if someone knows 1 linknetwork that can prove me wrong id be glad to find out!