I don't believe there's any doubt Reynolds possesses serious power, but I'd probably associate drafting Reynolds within the first five rounds as the equivalent to drafting Adam Dunn so high. He surely has the power to support a 30-35 HR campaign at the least, but he still strikes out a lot (on pace for 212 K) which can make him more prone to average fluctuations year to year. If that average is on the downside (let's say .250), he'd need to support that with premium power and double-digit stolen bases. That said, even though Reynolds has a lousy contact rate, he's not quite as clueless as his strikeout rate makes him out to be. Also, the fact that the quality at 3B has been at a dearth this year, will mean that there's some justification for Reynolds being taken in the first 4-5 rounds easily. Would I draft him first round? No I wouldn't, it's like drafting Ryan Howard at scarcer position with more risk, but I believe 4th/5th round is where I'd roll the dice (I doubt he goes that far down next year).
Beltre and Reynolds are not very similar. The question with Beltre was mostly power. No one doubts the power is real when it comes to Reynolds. The worry is that the steals disappear and his average falls to .230. He's not going to morph into a 15-20 homer guy.
But Beltre hit over 20 HRs in 7 of his 10 full seasons, and in 3 of the 4 seasons since his money year, he had at least 25 HRs.Reynolds had 28 HRs last year, and as the charts show above, they have very similar SLG% for their age. Reynolds is a tick better, but the difference isn't massive. On the other hand, Reynolds strikes out about one million times more often than Beltre, and has had a worse average.
At most, the difference between them is probably 15 points of BA in Beltre's favor and 5 HRs in Reynolds' favor.