When I sat down to analyze these two players, I figured the numbers would be interesting. While these two guys seem to have similar toolsets, they are also somewhat different players in terms of what scouts seem them as in the future. If you're confused, just read on.
Fowler - 6'4", 175 lbs, born 3/22/86. Selected in the 14th round of the 2004 draft and bats switch.
Jones - 5'11", 180 lbs, born 6/25/87. Selected in the 3rd round of the 2005 draft and bats
If I recall correctly, both turned down football scholarships to play baseball. I know Jones did for sure. Scouts drool over both of these guys' toolsets, as they both seem to have that "5 tool" potential. Fowler's frame though is significantly larger, and scouts unanimously believe that he will flash significantly more power once starts growing more into that frame. Meanwhile, Jones is pretty built as-is. He actually weighs more despite being 5 inches shorter. Based on frame alone, I would say Fowler has more power potential.
Fowler - Posted a .273/.397/.367 line at Modesto (Cal League). In 245 ABs, he had a 64:44 K:BB ratio, 2 HRs, 7 2Bs, 5 3Bs and 20 SBs. His IsoP was .094 - not very good for the Cal league. He also suffered a broken hand that caused his season to end early.
Jones - Posted a .217/.304/.296 line at Quad Cities (Midwest League). In 419 ABs, he had a 94:41 K:BB ratio, 4 HRs, 15 2Bs, 3 3Bs and 22 SBs. His IsoP was .079 - not good but not horrible for the pitching-slanted MWL.
Both guys after 2007 were looked upon as guys with all the tools to make it, but both struggled mightily.
Fowler - Posted a .335/.431/.515 line at Tulane (Texas League). In 421 ABs, he had a 89:65 K:BB ratio, 9 HR, 31 2Bs, 9 3Bs and 20 SBs. His IsoP was .180 - an impressive number given his age and speed.
Jones - Posted a .316/.407/.483 line split between the FSL and Texas League. He compiled 307 ABs in the FSL (a very pitcher-friendly league) and 124 ABs in the Texas League. His IsoP was .150 in the FSL and .210 in AA - good for a .167 blended rate. He had 13 HRs, 17 2Bs, 8 3Bs and 24 SBs, with a 97:55 K:BB ratio.
Both guys had outstanding years. In roughly the same number of total ABs, they had basically the same number of Ks, with Fowler having 10 more walks. Still, Jones has shown a lot of patience himself. Both have flashed very good speed, with Jones grading out slightly ahead due to the success rate on SBs (24/30 vs. 20/28 for Fowler in 2008). The power displayed in 2008 was roughly equivalent, with Jones hitting more HRs but Fowler having a ton more 2Bs. That 31 2B total supports the argument that Fowler will likely flash more power down the road, as those 2B typically starting turning into HR as the player gets stronger and learns to square the bat more with experience.
Fowler definitely has more power potential. He could legitimately become a 25 HR guy in the bigs. Meanwhile, Jones is more likely to top out around 15 or so. They are fairly equal in the speed category, with Jones having a small handful more SBs. If Fowler has 25/40 potential, I would feel comfortable saying Jones has 15/50 potential. Defensively, Jones is good but he has been playing LF. I am sure at least part of the reason for it is the existence of Colby Rasmus. That being said, Fowler has the definite advantage here. His D in CF has been labelled as potential gold-glove caliber.
Basically, we are saying offensively the difference between the two is what we all thought Carl Crawford could be vs. what he actually was in his first few years. The gap exists, but I do not think it is as big as a lot of "experts" have made it out to be. Assuming Fowler is a top 10 prospect, then Jones should be a top 50 guy. Jones is a full year younger than Fowler, reached the same level as Fowler, and brings a somewhat similar game to the table.
As always, if you disagree with a point that was made feel free to discuss.