There are several things that I look for on TER before I make an appointment with a provider.
1. A decent sized sample of reviews. If a provider only has a few reviews I'm not going to take one for the team.
2. Consistently good reviews. For me, this applies to the number scores and also for the written account. I actually get more out of the written part of the review than the numbers but the numbers do show, in a rather quick fashion, the relative consistency of the provider. If the numbers are all over the place I'll move on. If the numbers, and especially the most recent ones, are 8s, 9s & 10s then I'm definitely interested and will read the written part of the reviews.
3. As far as looks go, sure I look at the number score on the review but I also look to see if she has posted pics on the regional ad board and on the photos only board. I do this because it is more than likely that these are the most recent pics the provider has and are a true representation of her appearance. I really only hobby in Las Vegas and fortunately there are a lot of providers that post pics on both of those boards.
After a while I get a good feel for who is actively posting pics on TER and that is what usually generates interest in a particular provider for me. From there I look at the reviews and read the most recent ones. To the question that the OP asked about current reviews I guess it all depends on what current means. A three or four month gap doesn't really raise any flags, but more than a year would cause me some concern.
4. This doesn't have to do with reviews but I have yet to schedule an appointment with a provider who is not on P411. TER and P411 work in tandem very well and they are well worth paying for, IMHO. (I'm not bashing non-P411ers)
Anyway, that's my process. The providers I've seen have all been well reviewed providers who don't play any games with the way they advertise their appearance or services and I truly believe using information from the reviews (quality, frequency & consistency) is the number one reason for all the great sessions I've had.
I realize I went a little beyond the scope of the OP's post but thought that what has worked well for me might be of use to someone else.
Cheers