my thoughts.....
This is a rather interesting and potentially contentious thread. Personally, I've just moved from a Vision Impulse to an Angel, so have some experience re cost in this instance. The reason for this are twofold:
1. Vanity
2. Comfort level with Space frame and the IR3 is much tighter
Since you kinda exempted Vanity from the argument (to me it was worth the premium, although I do dearly love my Impulse still).
For my experience and skill levels diminishing returns likely kicked in when I spent more than a Spyder on a marker. Being a novice I still have a huge amount of field craft (playing tight, when to move, snap shooting, communicating etc) and skills to learn. It's very often not the marker that made the hit but the individual behind it. If I get tagged in a game no matter what they are shooting, it was because the individual had better technique and skills than me. Listening to how these guyz / girlz shot me out was more important to me than the marker they used (silly use of cover, not tight enough hence two in the back of the head with an inferno - fair enough!)
hmmm, am I answering the question, well not quite.
What I have acquired with both markers though is exceptionally reliable, accurate and high rates of fire (ROF). This enables me to have some competitive edge in a game, and I can put a lot of paint in the direction of an opposing player. The more paint the more chance of tagging him out. Also on a sup-air field the speed of play often means that only milliseconds are available to get out from behind the bunker acquire target and shoot. This is an exceptionally important skill to learn but obviously comes with time, experience and mostly practice. Also if my marker is "up", and I'm firing, having 14 bps bouncing of your bunker is something very difficult to snap shoot out from, hence I could be pinning in a more experienced player. A debatable point though is this worth the additional cost???? To a point it is. We played some concept and speedball games recently where a couple of impulse's and top end cockers went up against and a larger number of playerz all with Spyders, tippies and e-mags. To cut along (and at times amusing story short), the day was very one sided. Although a number of factors went in our favour (being a smaller team was one) the skill and experience base was well matched, the high-end markers definitely made huge ROF difference in these games. Even some players with very good field sense and a lot of experience admitted it was not a pleasant experience being on the end of so much "inbound". Saying that it was still a very friendly day out!
Here endeth the lesson.............. not likely....
A couple of factors which will should also have an impact on "Bang for your buck"
1. What are you playing rec-ball or tournament. If Rec-ball is your bag and your a bit of a sniper I've heard many people say you can't get better than a Tippman with a Flatline barrel nice flat trajectory range of an ICBM. Also substantially cheaper than any top-end electro's and cockers.
2. Re-sale and trade in value. One quick look in the classified section should tell you all about that. The interest in Angels is phenomenal, and they still command pretty good re-sale values. Also the depreciation on Angels is lower than that on Impulses etc. Since many people comment that you trade up very quickly this should be considered.
3. Cost and upgrades. I may have to disagree though re the Angel being 1000 GBP more than the Impulse. Once upgrades come in to play the cost of Impulse ownership can exceed Angel. Sure the I-frame, delrin bolt, cricket board, freak kit made me shoot much faster and more accurate, but total cost exceeds that of an Angel. Out of the Box the Angel is brilliant value
hmmmm, likely to get flamed on this post, perhaps the most important factor re diminishing returns is personal preference. Spending 1000's on markers won't make you a better player, I personally believe high ROF "can" make you more competitive, but the cost of this is relative to each individual budget. Also I've left behind my student years many moons ago, lack of wifey and kids means a small disposable income to feed Paintball with hence my cost / return factors are a little different to players on tighter budgets. Ok so that's my 10p worth back to work. I'm sure some of you will think "I'm depriving a village somewhere of it's idiot", but anyway....
laterzzzzzzzzzzzz
(overly long fell asleep whilst composing)