I used to be in the same boat that you're in, I was worried about the additional weight among other things. I was, and still am, a huge fan of the 2000 size Stradic for certain applications. So I was kinda bummed when Shimano first discontinued that size reel and went up to the 2500; the keyword is "was."
For my longer rods I found the 2500 really balanced them out much better. I only use the 1000 size on rods at or less than 6', or much lighter powered rods for panfishing or walleyes. A few years ago I purchased a St. Croix Avid AS69MLXF for jigs and grubs. Even before I put line on a reel, I attached a 1000 Stradic to the rod. It was way to small to balance it out for my taste, so I went up in size and really love that combo.
I also found that the 2500 gave me increased casting distance. And chances are if you're scaling down to a spinning outfit, the fish are finicky, so you'll want to cast to them from a good distance away as not to spook them.
I really love my 2500 for longer rods in a medium power. Anything shorter or much more finesse orientated, I like my Stradic 2000's. Although, If I didn't have any 2000's I wouldn't hesitate to use a 2500, they are great reels.
All-in-all give the 2500 a shot, I don't think you'll ever look back. With this reel you'll definitely increase your amount of applications and techniques. And if you're still kinda sketchy on them, scour online auctions for a 2000 size Stradic, you can still come across a new one every now and then. Also, Daiwa currently makes a 2000 and 2500 size in their Sol, Fuego, and Tierra spinning reels. Hope this helps.