Martin Logan speakers

I have a pair of Acent i, with a Martin Logan Desent i subwoofer. I power them with a SS Musical Fidelity intergrated amp, for a modesty priced system they sound fine to me.

To the OP, I haven't listened to Vistas specifically, but I've owned an older model in the Aeon i's, and a newer model in the Expression 13As, and I can say that yes MLs are very directional, and yes panel to woofer integration hasn't been a strength of theirs, but both of these are much improved with the newer models, imo.  I'm not sure where the Vistas sit in this spectrum, but If you can get a good deal, and you have a dedicated room where you can really fine tune the listening and speaker positions, then electrostats can be magical.  Don't throw them in the corners of a multipurpose living room and expect to get the same results.  

As for the 13As, I decided to stick with ML when I chose them over other dynamic / cone speakers like the Sopra 2s (which I also really liked) because they just blew everything else I demoed away in terms of imaging.  I will grant that you are probably giving something up in terms of dynamic slam vs a cone speaker, but larger panels help, and so do subs, so I'm not lacking for dynamics or low end extension. 

I still went with MLs even though I'm primarily a rock and electronic music guy and could afford more expensive dynamic speakers.   Hope that helps. 

I bought a pair of impression 11A’s last April, and I love em! 
Owned many many speakers over the years and these are one of my favorites. Bass is seamless to these ears.. I just wish I’d have gotten the 13A, for a little bigger soundstage and bass wallop (but these speakers can rock out in my 14’ x 25 basement listening room ..

Even though they aren’t for me, I completely get why some people love ML speakers and find most other types wanting.  They have their own sound that if you love it, you love it.

To the OP: don’t be put off by anyone else (like me) who prefer other speakers.   

I think that when people start talking about “enough power” as a issue to whether an amp is going to sound good on a speaker or if more power is needed, they really don’t have much experience in hifi audio. The only reason one needs more power is if the amp is running out of power while playing music. Aside from that, no one can really tell you what amp is going to sound best in your particular setup/room. There can be recommendations but ultimately you have to find what amp works well for you. I think it is a silly question to ask if ML’s are still considered good speakers. ML’s are great speakers! One of the most desired sounds in Hong Kong is the older Monolith ML with Conrad Johnson Premier One tube amp. I own the Request and have tried many amps on them. I like the way a really good powerful EL34 amp sounds on my ML’s but for my setup/room, I found a Class A 50watt Threshold to be the best match.