Would using one of the newer gTLDs have any adverse effect on SEO?
Google published this today which answers this question well and in detail.
With the coming of many new generic top level domains (gTLDs), we'd like to give some insight into how these are handled in Google's search. We’ve heard and seen questions and misconceptions about the way we treat new top level domains (TLDs), like .guru, .how, or any of the .BRAND gTLDs, for example:
Q: How will new gTLDs affect search? Is Google changing the search algorithm to favor these TLDs? How important are they really in search?
A: Overall, our systems treat new gTLDs like other gTLDs (like .com & .org). Keywords in a TLD do not give any advantage or disadvantage in search.
Q: What about IDN TLDs such as .みんな? Can Googlebot crawl and index them, so that they can be used in search? A: Yes. These TLDs can be used the same as other TLDs (it's easy to check with a query like [site:みんな]). Google treats the Punycode version of a hostname as being equivalent to the unencoded version, so you don't need to redirect or canonicalize them separately. For the rest of the URL, remember to use UTF-8 for the path & query-string in the URL, when using non-ASCII characters.
Q: Will a .BRAND TLD be given any more or less weight than a .com?
A: No. Those TLDs will be treated the same as a other gTLDs. They will require the same geotargeting settings and configuration, and they won’t have more weight or influence in the way we crawl, index, or rank URLs.
Q: How are the new region or city TLDs (like .london or .bayern) handled? A: Even if they look region-specific, we will treat them as gTLDs. This is consistent with our handling of regional TLDs like .eu and .asia. There may be exceptions at some point down the line, as we see how they're used in practice. See our help center for more information on multi-regional and multilingual sites, and set geotargeting in Search Console where relevant.
Q: What about real ccTLDs (country code top-level domains) : will Google favor ccTLDs (like .uk, .ae, etc.) as a local domain for people searching in those countries? A: By default, most ccTLDs (with exceptions) result in Google using these to geotarget the website; it tells us that the website is probably more relevant in the appropriate country. Again, see our help center for more information on multi-regional and multilingual sites.
Q: Will Google support my SEO efforts to move my domain from .com to a new TLD? How do I move my website without losing any search ranking or history? A: We have extensive site move documentation in our Help Center. We treat these moves the same as any other site move. That said, domain changes can take time to be processed for search (and outside of search, users expect email addresses to remain valid over a longer period of time), so it's generally best to choose a domain that will fit your long-term needs.
I wouldn't say so, because, first of all, it contains some of the keywords and keyphrases when combined with a domain name, and second of all, who else is keeping track with all this more than Search Engines?
I have seen these new gTLDs used on Russian internet by people making a living out of SEO and they do not seem to have any problems. Besides, domain name is playing some minor role in search results, but not as big role as the content.
Short answer. No. No issues what so ever short of performance metrics.
Long answer. TLDs are scored for quality over time and that a .de site would be preferred over others based upon it's reputation. With any new gTDL, these metrics do not exist yet. As well, the search engine penetration any new gTLD is not known. It is assumed that .museum would enjoy the same penetration as .com which is a good thing. The risks are these: How are search engines going to view the gTLD in the future? For example, will .ninja preferred within certain countries and not enjoy the same penetration as .com? Is .museum going to have higher quality sites than .ninja? Remember that Google does load-balance their various sites based upon interest and past performance. For example, .ninja may be more popular in the U.S. than in Poland. However, .museum might enjoy interest globally.
There is some level of risk based upon what is not known. I rather suspect that the risk will be small. The examples above should help you to formulate any decision you may make.
The new gTLDs are not inferior to .com in a technical way. Google's Matt Cutts has spoke about this in video.
What you need to watch are country specific because they do carry more weight for the country they are issued for. He has also talked about this on video.
UX is a large decision maker for me. Depending on which one, some look spammy and users may not react to them well.
No, not at all. but they are not very good as well, as they don't carry any SEO value.
Besides, they're not as powerful as cTLDs or TLDs, both have some value associated to them. Like cTLDs clarifies that these domains are in close association with particular geo location. and TLDs specified if the domain is for commercial purpose, etc.
Google just stated they would not make any differences between the different domain extensions. With the exception of ccTLDs when it comes to geotargeting. The new local gTLDs, such as .london and .berlin, however, will be treated as gTLDs and not as ccTLDs (or whatever we might call them one day). For further reference, please see http://googlewebmastercentral.blogspot.ca/2015/07/googles-handling-of-new-top-level.html. So in order to answer your question: no, the new gTLDs won't hurt your SEO, but they won't boost it either. It all comes down to providing relevant, high-quality content, etc. etc.