The Opto Striker is the best place to start and the River could be a good compliment to it. The newer runs of Opto Strikers (2010) remind me of an Orc while the first runs (2009) seemed more like a Leopard.
I am not a big fan of either the Core or the Fuse, but of the two it seems the Fuse is more versitile. The Core has too much glide for me, reminding me of the Comet. This could be useful for longer approaches if you have great accuracy, but I have a tendency to occassionally release to the right when I try too hard to throw straight. I need something that has a little fade just in case.
The Pure is a great putter but the Zero Line gets knicked up way too easily for my taste. It approaches very well (50 to 100 feet) at moderate power since it does have good glide and its LSS understableness kepts it from fading. It does make a great driving putter if given enough hyzer as it will hyzerflip about half way through its flight.
The Riot is hit and miss because of the inner slanted rim. It really depends on how secure your grip is, and if you do not have a secure grip that you do not overdo it and then griplock your throw. It is very Wraith-like.
I never got over the novelty factor of the Blitz; it reminds me a lot of a very overstable XCaliber. The L-shaped wing only feels funny in your hand if you intend to give it an anhyzer release. I found that it had tremendous HSS and would not hold an anhyzer line for more than a second or two. It gets very respectable distance on a spike hyzer though.
I cannot say much about the Vision. On the very first throw with my Vision, its incredibly high speed understableness surprised me, launching itself immediately to the right, and I lost it in knee high grass (damn me for thinking clear opto plastic looked cool). My Monarchs seemingly threw better so I did not feel a need to rush out and get another Vision. I have been told it is much like a slower, glidier version of the Monarch (because it has less lateral movement than the Sidrewinder or Roadrunner).
I really love the Opto Halo and if I was not completely rocking my Z Nukes, I most likely would be using the Halo has my main distance driver. It is great for flex lines and handles the wind decently. The plastic gets a little slick when wet, and the slight slanted inner rim may be affected then, but otherwise it is not noticable. Its flight is similar to the Z Nuke, maybe 20 feet shorter, so a lot of players are capable of throwing it. The Gold Line Halo has a lower HSS, making it more suscepitable to flipping, but it is far better than the ESP Nuke in handling winds. It is great for hyzer-flipping or mild hyzer lines.
If I needed to, I would feel perfectly comfortable going with an all Lat64 bag with the remaining discs I have: Halo-Striker-Fuse-Pure. I would consider buying the River, but first I have about 40 discs I need to unload because I should not spend any more money this year.