Hi John,
I have had my .25 Streamline since the beginning of the year, have shot thousands and thousands of pellets through it, and absolutely love it. Here is a couple pictures of mine.
and here is a dove picture shot at 75 yards...
I want you to know that I have owned a Benjamin Marauder and can give you a pretty fair comparison of some features. But up front let me say that my recommendation would be for you to get a Streamline instead of modifying something else. The Streamline is a work of art and extremely accurate, and I also love its simplicity. As you can see I run an Athlon Midas 2.5-15x50 SFP scope on her, with a Leapers Sidewheel, Vortex flip up/lay flat scope caps, a Harris Bipod, and a Huggett Belita. I like the look of the free floating barrel better than the shroud. I have mine setup to shoot the JSB 34gr. Heavy pellets at an average velocity of 830 ft/s which yields about 52 ft./lbs energy at the muzzle, with 29.67 ft./lbs energy remaining at 100 yards, and 26.65 ft./lbs energy remaining at 120 yards. Now for some comparisons...
The Streamline weighs 6.6 lbs + 1.5 lb. scope = 8.1 lbs vs. the Marauder weighs 8.2 lbs + 1.5 lb. scope = 9.7 lbs. For walking, stalking, and shooting offhand while hunting the Streamline definitely has the weight advantage.
I personally prefer the mechanical advantage of the Streamlines side lever vs. the Marauders bolt cocking lever.
The Streamline has a power adjuster wheel vs. the Marauder does not. This comes in handy for hunting where 18 ft./lbs or 30 ft./lbs is more desireable than 50 ft./lbs energy.
I prefer the hunter style safety on the Streamline vs. the safety in the trigger guard on the Marauder. I use mine the same way as Quintoona...I have it set so that I can only put the safety all the way on if the rifle is cocked, otherwise I can only put it halfway back when uncocked. Which for me is a great feature that I use all the time so I don't have to wonder... I just move the safety lever and it tells me if I am cocked and loaded.
My Streamline produced 30 shots out of the box vs. the Marauder is rated for 16 shots. So the Streamline delivers twice as many shots as the Marauder does. However, I have a Huma regulator installed in my Streamline which yields 51 shots before it falls below the regulated pressure.
The Streamline has a completely adjustable honest two stage match grade trigger that can be adjusted very easily as low as you like. For target shooting I have eliminated the first stage completely and have mine set to just a couple ounce hair trigger. I actually have it set dangerously low but I am the only one that is allowed to shoot my rifle, and I always make damn sure where it is pointing before I cock it. I would reset it for hunting though.
The Streamline has the look and feel of a real rifle to me and is more than accurate enough to take small game out to 120 yards or more. I routinely shoot at targets at 100 yards at the range, and I also shoot at little paper cone drinking cups I put out on the hill that is 21 yards behind the 100 yard line. I can hit them with the greatest of ease with my Athlon Midas 2.5-15x50 SFP Scope, and just as easily with my Bushnell Accelerate 4x Prism Sight. And I can hit those paper cups out there on the hill at 120 yards standing offhand more times than not. It is very well balanced and "points" instantly when I mount it to my shoulder.
This rifle has a 250cc air tube that can be filled to 230 bar without giving yourself a heart attack. Especially if you fill it to 3000 psi (200 bar) with your scuba tank first, and then just top it off to 3335 psi (230 bar) with your hand pump.
One outstanding difference is the price...you could buy two Marauders for the price of one Streamline. But I promise you will not regret purchasing a Streamline. My rifle will shoot 1/4" to 3/8" groups at 50 yards with no wind, and 1/2" groups if it's windy...and it does this almost effortlessly! If I told you she will shoot 1" three shot groups at 100 yards on a calm day you may not believe me...so I challenge you to see for yourself. You will not have to worry about stopping a charging Jack Rabbit at 100 yards with your Streamline!
All the best, Chuck