200/400 against Nenad Medic difficult river decision

[Chaoslord]

about 30mins on the table, never played with him before. ive shown down only winners so far so my image is probably strong, tight agressive
he has been playing too loose and a little donkish, no specific reads yet.

Full Tilt Poker Game #3205122263: Table Canfield (6 max) - $200/$400 - No Limit Hold'em - 21:47:31 ET - 2007/08/09
Seat 1: xdhaj ($88,842)
Seat 2: monkey1001 ($48,811)
Seat 3: Aeron73 ($40,866)
Seat 4: ZRC ($0), is sitting out
Seat 5: tkdcrew ($41,072)
Seat 6: Nenad Medic ($61,162)
monkey1001 posts the small blind of $200
Aeron73 posts the big blind of $400
The button is in seat #1
*** HOLE CARDS ***
Dealt to xdhaj [Jc 8c]
ZRC adds $7,099.50
ZRC has returned
tkdcrew has 15 seconds left to act
tkdcrew folds
Nenad Medic raises to $1,200
xdhaj has 15 seconds left to act
xdhaj raises to $3,900
monkey1001 folds
Aeron73 folds
Nenad Medic calls $2,700
*** FLOP *** [Jd 7c Qs]
Nenad Medic checks
xdhaj checks
*** TURN *** [Jd 7c Qs] [8s]
Nenad Medic bets $5,200
xdhaj has 15 seconds left to act
xdhaj raises to $15,200
Nenad Medic has 15 seconds left to act
Nenad Medic calls $10,000
*** RIVER *** [Jd 7c Qs 8s] [Ac]
Nenad Medic checks
xdhaj has 15 seconds left to act
xdhaj has requested TIME

is there value in betting the river? i have a little over potsize left.