Yes, there is a benefit: You have your small race's benefits!
In just asking about playing a small character, you're leaving out something important: you don't play a small character, you play as a small race and have their unique benefits!
- You get to be a Kobold (+2 Con, and +2 Cha or Dex), with some bonus survival abilities and a racial Encounter Utility power which boosts your party's mobility.
- You get to be a Goblin (+2 Dex, +2 Cha or Wis), increasing your own mobility and deceptiveness.
- You get to be a Halfling (+2 Dex, +2 Cha or Con), who, along with a couple of minor defensive bonuses, gets an encounter power to force an attacker to reroll, possibly saving your life.
- You get to be a Gnome (+2 Int, +2 Cha or Dex), which along with making you stealthier, lets you start combat with stealth and lets you pop invisible when you're in danger. In addition, you can use Ghost Sound, and as someone used to trickery, you have a bonus to saves vs illusions.
- You get to be a Svirfneblin (+2 Wis, +2 Con or Str), enabling you to altogether ignore some forms of difficult terrain and gaining a defensive encounter power that gives you partial concealment and temporary hit points.
You also gain access to their racial feats and skill bonuses, as well as feats which are exclusive to small creatures. There are other small advantages these races get that I left out for brevity. Those are your advantages to choosing to play as a small race. Pick the ones you want, and if you don't want any of them, play as a race you do want to play!
Are they worth the trade-off of the small race's disadvantages?
Only you can really answer that. The answer is the simple and universal answer: does this race suit you?
No, small races don't get counterbalance for their limitations - they just target people who don't care about having those limitations. Note well that the limitations of a small character are very situational: not everyone expects to bull-rush and grab large opponents, jump well, or wield two-hand weapons or hold versatile weapons in one hand. These are not things that everyone cares about doing.
If I make a Gnome Wizard, I don't really care about having those limitations, and her racial perks will be fantastic for her class.
If I want to make a fighter, though, those limitations are bad. Being able to do that stuff matters to me, so I would not pick a small race.
The limitation I didn't mention - shape changing - is something someone might actually be able to take advantage of, specialising in making effective use of a few particular small shapes.